yeah i've been down this road and so have most people with stock-ish peugeot setups.
i'd say if you're going the 3'rd transfer route get a good used Vogue cylinder (get ahold of christophe(tomahawktuning), johno (blkblk) or chad burke or someone who has stacks of euro shit laying around. Those can be ported out pretty aggressively and run the big pipes.
if you're really against a big pipe, the simo circuit is OK. I have it on my sachs and i think its doing its job down there. It has broken like 50 times and been rewelded, but thats most pipes for ya, and at first it wasn't very well secured. The powerband on stock is really high and comes on kinda weak, but it pulls well from 8k upwards.
i'm not sure what to think about that simonini on '77... haven't heard much about it.
the other pipes are pretty much a joke, from what i hear. I've tried getting a FACO to work on my bike after a lot of modification, and it isn't bad, pretty torquey actually, but this is variated and i want it to wind out!
i've got a new stock-ish peugeot circuit pipe option in the works right now. I'll probably have the prototype worked out this weekend then its a matter of testing and getting the mounting perfect-o to clear everything. It might be on shelves in a month or two or if you want to email me i might be able to get you a test version. I'm pretty excited...