Scrypt is the least profitable due to all of the asics. Scrypt variants (Scrypt-N, scrypt-jane), X11, X13, and any other non-ASIC implemented algorithms are still profitable by usage of GPUs.

intron or c-scape, how did you guys make your modified usb hub? I really would like to know. If it is possible, could you point me to some design? I would like to make my own and not buy pre-made.

Are you still continuing this? If not, do you have plans to open source this?