I think I m not the only one here to have strong technical knowledge, you can give me some ideas.
I m giving my point of view about somes importants aspect and voices you have to choose to construct humanoids robots.
If you interesting in it you can use the same king of construction and give your own vision it could help me to think about it.
1 : Global configuration
I don t believe it is a good idea to put IA circuits into the head,(The needed miniaturization will increase a lot the price of the robot that s useless) A robot don t need to breath and there is a lot of free space under the chest, for me as a ingenior this is the best place for IA.
I also think you should not put IA in the bot abdomen, Battery are always heavier than circuits, and for repartition of the fembot masses you need to put heavier things near of the ground.
I think the ideal configuration is
Heads:
Dectors as camera, sound detectors and mouth speaker.
A good facial animation could take a lot of space in the head.
Don t put too much things in the head
Arms:
Nothing special I would use Lighter componant for arms
Chest:
IA ciruits and connectivity
Abdomen:
Pneumatic systems with a good soundproof and sexual systeme
Thigh :
Fuel cells battery for mass repartition
Legs :
Heavier componant
Feet :
Add a ballast
Last point what kind of structuration fot a fembot ?
Personaly i think about an aluminium squeleton quite heavy (not too much) with a hard plastic shape glue on it. This shape is lighter than the squeleton and make an external grid supporting artificial skin, all the internals organs are attached to this plastic shape.
2 : Artificial Intelligence.
What could be the solutions about:
2a : The technology:
Their is the classic eletronics technology, their is also new thing like Quantum computeurs:
A classical computer has a memory made up of bits, where each bit holds either a one or a zero. The device computes by manipulating those bits, i.e. by transporting these bits from memory to (possibly a suite of) logic gates and back. A quantum computer maintains a vector of qubits. A qubit can hold a one, a zero, or, crucially, a superposition of these. A quantum computer operates by manipulating those qubits, i.e. by transporting these bits from memory to (possibly a suite of) quantum logic gates and back.
The technology is really more powerful and by definition this is nanotechnologies cause you knows that quantum appears only at very little scale.
I believe in this technology to became the base of realistic IA for robots, and I m not the only one.
2b : The programming:
I think there is some experts in this community to talk about this better than me.
Anyway, I think the 3 asimov rule are a first kind of "consensus" for almost everybody.
I think that the second law should be move after the third one.
After there is so much kind of robot and specific programming.
For a basic sexbot programming don t seems too complex, but for advanced bot we have to find new way of programming
Some question:
Do you think that advanced programming should be able to modify some aspect of their programs, wich ones ?
3 : Energy And motors
What could be the solutions about:
3a : The mouvements:
The more efficient solution is a pneumatic solution , (Actroids are already using pneumatic solution but their motor are outside of the robot that the main probleme)
For a true autonom fembot you need a motor into the robot.
I think to a solution here is what I find

This is a magnetic pump Wich need 60W power supply with relativ pressure forces of -380mbar wich is enough to move and support a 40Kg Body, the other positiv point about this technology is that this kind of motors are not noisy (20db) and a almost perfect soundproof is possible. You will need maybe 3 or 4 like this one in the robot.
A last interesting consideration is that I don t believe in the ultra heavy fembot a think that these kind of robot will be really lighter than a "normal" female.
3b : The powersupply
So we still need 3 or 4 the 60W power supply, our actual Computeur battery have a 10W output power for 1Kg.... so at this level the only realist and efficient solution are Fuel Cell methanol battery this is very high tech devellopements but somes corporation as Toshiba, Nokia... are working hard to devellop these systems and they are near of their goal
More at
http://en.wikipedia.org/wiki/Fuel_cell
It mean that you will have to supply your "friend" in methanol, I think around 400, 500 cm3 of methanol per days, a 10-20 hours autonomy is totally possible.
Methanol cost is 5$ per liter.
4 : Functions or specificity
What could be the functions ability or specificity you are waiting for:
Sex: well yes
Domestic task: If she is able to do it well its ok but it is not my priority
companionship: That s something important for me
Secretary: She could be able to wrote letter makes operations on computeur by a manual way(not a direct link) She is preprogramming to have notion in mathemtics and science wich could be useful if your are a student
Defense of you or your home: I don t want a battle bot
Body spec
Artificial breath : Important feature for my specialy the chest mouvement simulating this
Mouth and vagina fluids : Important
Artificial Sweet: No I dont want it
Ability to bleed : Absolutely not
Capacity to eat: I dont want it
Capacity to drink : Same thing that useless and its a silly kind of risk
Options
Aware or unaware : Aware for me
Device or not: I don t want to use a remote device on my "wife" except if she has a serious problem,so the device is not useless, after that I want to have a human interaction with her and the first part of it is to respect her
Informatic connection : I like the ideas to connect her to my computer, she stay aware during the operation and can use all the capacity of the machine