Sorry for snapping at Nlandas, but the Buddha and USB cards are (just IMHO) two of the most over-rated, over priced bits of Amiga hardware there are. It really gets me worked up when people recommend them without qualifying why.
USB is not a good solution JUST for Keyboard and Mouse (technically or economically). If you absolutely NEED USB for other things (USB-Key, scanner, printer etc.) it becomes justifiable, I guess. It will still piss you off the first application you come across that the keyboard doesnt work :-)
Again the buddha, as an IDE controller, just doesnt have enough advantages over the internal IDE to be justifiable (again, just my opinion).
But
If you need a catweasel (cos the new ones have buddha built in) and a clock port for another expansion, then it becomes more attractive.