It's a Chevy with a roomy engine compartment so the only limit is your budget. Time to cruise craigslist and the junkyards. Like Jody said, an LS motor would be sweet and pretty easy and have been around long enough now that there's bound to be some deals. Others can chime in on this but what about an iron LS truck motor? Far cheaper than the aluminum car motors and more plentiful if you don't worry about what it looks like and the 6.0 makes around 350 hp bone stock. That's headers, a K&N filter and a computer flash from 425 hp.
If you want to go efi on a lower budget, shop for an LT1 from old cop cars, Camaros and Corvettes. Less hp and displacement but have lots of aftermarket support.
And just in case you haven't seen the Rad Rides Hurricayne, this is required reading
http://www.popularhotrodding.com/fea...yne/index.html
On suspension, Global West makes tubular control arms for them and Air Ride might have some stuff too.