if you don't need to worry about any emissions or inspection stuff, then you have tons of options, you can pretty much take ANY manifold that wil bolt to your heads, and convert it to MPFI which can run off the stock PCM or the 411. check out the work this guy has done:
http://www.hotrodsolutions.net/
he is the one who did the work on my manifold, I actually purchased my manifold already completed, so I didn't ever have any contact with him, but the work he did on it was excellent.
you also have great options like the ramjet, which I really like, or something like the holly/weiand stealthram seen here:
the thread about the marine intake is a wealth of information regarding any MPFI manifold swap so even if you don't plan on running a marine intake, it will still help out tremendously with things like wireing and sensor placement, etc.