I personally would just buy the cheapest one that works. It's not like you're ever going to use it for anything else :) I think most come apart the same way, the blade separates from the container and that's it. I haven't seen any too much more complicated than that. Mine is a bit more complicated but i wouldn't use it for FT, I would buy the cheapest thing i could find for that purpose and toss it after.
i wonder if one of those magic bullet blenders would work?
www.amazon.com/Magic-Bullet-MBR-1701-17-Piece-Express/dp/B001WAKFDY/ref=pd_sim_k_4?ie=UTF8&refRid=10QE8555FH1Y2205M19Q