The HRC Stage IV comes with
JE Forged Pistons, piston rings, and wrist pins
Crower billet connecting rods
625 CC Fuel Injectors
Hahn / ACCEL-DFI Engine Management Computer System
Hahn ignition amplifier
GReddy Type S Blow-Off Valve

Is this a good kit to buy or am I better off buying the parts seperatly on my own. If so what are the best Stage IV kit I can put together?

If your looking to throw down quite a hefty ammount of dough, you found yourself the right way to do it :-) Ask them how much of a deal they'll give you if you opt for the 20g instead of the 16g, you might get a good deal... cause rarely a person will spend the extra $$ for it so they probably just sit there at the shop.

I have a stage II right now with a fmic. I dont care about the money. I do want the best kit I can get. I would like to know if this is the best components I can get....is the hrc stage IV the best way I can go. Oh yeah and does the accel dfi take the place of the s-afc?

you could ask them about a stage 2 to 4 upgrade package.....

Yes you use the DFI instead of a s-afc to control your fuel. The DFI is a stand alone fuel management system but the gen 6 box can’t control spark because the gen 6 is for distributor type ignitions.

So in a way its just piggy-backed because it’s only controlling your fuel. The stock ecu is still controlling your spark but you have to amp it up and pull in out w/ the crane or msd.

The Generation 7 DFI can do both your fuel and spark but HRC doesn’t sell it because they are working w/ Accel on getting a full plug and play harness made.

The HRC stage 4 setup is nice, but it's so hard to try to fine tune the fuel maps and fuel enrichment/acceleration issues. Plus, the Accel DFI doesn't control ignition--which makes it very pricey for a unit that controls JUST fuel.

There are other setups in the works, i.e., the 8-injector setup and the Greddy E-Manage, but I'm not sure if anyone has a setup with those running 20 psi (correct me if I'm wrong here).

There was one guy (sorry don't remember the name) that ran 22psi on the EIC system. The Greddy E-manage will control up to 550's so I bet you can run 20psi w/ that. Murix is the only one that I know of right now w/ that but his car is down.

I want the best set up I can go with. Money is really not an issue. I have a HRC Stage II with a fmic, missing link, 3" greddy cat back, 3" high flow cat, ngk wire & plus, and a profec b. I am going to do my internals over the winter and I would like to know what the best set up as far as ignition, injectors, and fuel management.

If you can be a little patient, then you could wait for HRC to fine tune and work out any "bugs" with their "newer" Gen 7 setup. Call them up to see where they are with that.