I just got an SVT exhaust. That'll flow way better than the stock SE exhaust. I can't justify spending another $350+ for the Tru Bendz or even more for something else that'll just net another pony or two over the SVT. I reckon the SVT will give enough to be worth while working with the headers.
You're gonna make your own headers? Awesome Jim.

I'd reckon it would be a lot easier on you if you had a set of OEM exhaust manifolds to use as a template. Ya know for flange placement, etc. I had a second pair but I traded them for the new headers.
Fancy smancy intake, huh? Is that what you call a hacked-off MAF with a K&N filter stuck on it?
Whenever I can afford to move my battery to the trunk, I'm going to fabricate some kind of true cold air system; just gotta get the Red Top in the trunk and move the fuse box outta the way.
As for the heads, yeah that's a bit of work to install those. You'll have to reset timing, etc., etc. The cams are a lot hotter, though, so yes you will see a gain. But the biggest difference between the SVT Duratec and our SE Duratecs is how much better the SVT breathes. Swap on an SVT UIM/LIM/TB and a better intake and exhaust and you've practically made up the difference of the heads n such with a pony or two on top to spare.
Next planned on my econo box is the true cold air intake. After that, chip me and I'm out of the performance business. Hopefully I'll have those done before the HSV meet and I'll try to put down a couple pulls. So Phil, put me down for some runs if that's on the agenda.
I know this car won't break into the low 9's on the 1/8th, and that's ok by me. When I bought this car, I wanted to make it faster and better looking and sounding than it was when I picked it up. I think I've done that.