What a headache. I don't even know how to go about collecting these to keep the collection complete.
One of each part maybe?
Yeah, if I were collecting them I would go for one of each part. Probably some reuse of bodies or heads where needed to make a full droid that kind of fits together.
If you are looking for one of each part (minimally) you would end up with (eventually) 25 droids....
The break-down of domes is:
5x R2 (silver w/orange, red, blue, or green & red w/silver)
2x R3 (clear w/purple or red) (red not available yet)
3x R4 (white w/purple or blue & green w/white)
3x R5 (white w/red or green & black w/silver)
3x R6 (white w/purple or orange & black w/silver) (not available yet)
3x R7 (black w/silver, orange w/silver, silver w/blue)
3x R8 (white w/black or orange & black w/silver) (not available yet)
3x R9 (green w/silver, blue w/silver or red w/silver) (not available yet)
Then there are 13 trunks - 10 R2 trunks, 3 R7 Trunks (the R7 Trunk style is also used in R8s)
Then there are 10 styles of left/right legs
Then there are 5 styles of middle legs
And finally, for the Disney touch - there are 8 "hats" - four colors of mouse ears (which are available now) and a Yoda Ears Hat, Pirate Hat, Fedora & Goofy Hat (which are not available now)
So 25 droids for one each of the domes could result in having multiples of every other part (trunk & legs) except for one trunk (since 13x2 = 26, which is 1 more than the number of domes).
So like what Rob said - a MAJOR headache to getting a "complete" collection.
Yep...
So, anyone heading to Disney willing to pick up one of each droid part for me? 
I would wait a bit before trying for a complete set or cashing in a favor to ask someone to help you. While I don't regret doing what I did, I really wish that all the domes had been there or at least minimally that there weren't problems with the availability of Black/Blue/Red right legs.
If I had been able to make the bodies I want to eventually stick R6, R8 & R9 domes on, I could have built all of them and put "temporary" domes on those bodies based on current stock and then when someone else was able to help me, just get them focus on the 10 missing domes and I wouldn't care what bodies they built to go with them....