Your alternative is the
ZZ Fabrications manifold. It's the same deal where you have to pull the cylinder head off of the vehicle and have the stock plenum milled off. You do have the option of adding nitrous spray bars on the ZZ. It's impossible to give prices on porting and polishing, since everybody does it differently. While you have the head off the vehicle you are going to have to decide how much additional work you want done. You can do things like go to heavy duty valve springs, install hardened valve guides, and oversize your valves. I had mine done by
Scheid Diesel. If you are serious about it, your best bet is to pick up the phone and call your chosen shop to figure out exactly what you want to have done and what the total is going to be.
The ZZ's come in both top and side entrance versions. You can keep the intake heaters if you get the top entrance version like I did.