The 1994 and up magnum truck manifolds flip with manual steering pretty easy. Put the driver manifold on the passenger side, and vice versa... that will face them forward. They are cheap and readily available.

I can't say how much max power they will support, but mine based on weight/ET/MPH makes around 840hp or so with them. (3740lbs@142mph on 23psi) That's on a 360", that never turns over 6300rpm.

I've seen those ebay "turbo headers" around for a while now, but have yet to see them put on an actual car. They seem to leave a lot to be desired...