Yes they make IC's with dual inlets and outlets.. however, lots of guys just combine the inlet pipes to one before the IC and split later.

If you joined the inlet pipes into the ic and split them after the IC you could put a single bov after the IC before the split and get away with one.

You can make a manual boost controller but I really wouldnt reccomend it. Unless you want to be asking for trouble just buy a cheap profec B spec 1 and lie safe in the fact that you have stable boost control.

Eliminating variables is what making an odd car with an unstable past (those bi-turbo's are a BITCH to keep together from what I hear) have a slightly better future.