Steering Options

I'm looking for opinions on the various steering systems based on a few parameters.

I have a rather tight budget, but have decided to build a 451 from a 400 block that I have. My problem is that headers are going to be a 'must have' for this engine, but steering plays a large part on my options.

So given that, and that this car will be driven on the street 90% of the time. It's not a daily driver by any means... more of a weekend cruiser. What would you do as far as steering goes? The car is currently equipped with a power steering column/gear box, unfortunately it seems if I want to keep the power steering I have to use TTI or Schumacher headers, both of which carry a hefty price tag. Would it be worth switching to manual or has anybody experimented with a rack and pinion swap from a junkyard vehicle?

My opinions as it seems:
Keep power steering - requires relatively expensive headers
Convert to manual steering - allows more variety, and cheaper headers, but requires manual gear box and probably centerlink as well as input shaft.
Rack and Pinion - I'm not sure if this can be scavenged and I'm not sure what options it would give me as far as headers go. I do know that new conversion units generally seem to be far out of my price range.

Any ideas?