Im going to Akihabra next week to pick up a few things for myself. If there are any items your looking for let me know and I will see if I can find them. There is also a smaller shop across the street from my house that has some of everything.
Edit:
I go about every three weeks to the following stores: Retro Friends, G.Front, Trader 2 and of course Super Potato, in addition to some others small stores.