The GT40ps are a good performing head, but by the time you factor in the springs, machine work, special headers, you are pretty much almost to the point where you can buy a decent set of AL heads.
Of course if you get good deals on the above it's one thing, but when I was gung ho on a set of 40ps and paying market rate for the machine work and components. I decided to buy the TFS heads. My 40ps are literally propping open a door in my basement today.
In a budget build, you can always just slap em on and let er rip. I wouldn't hesitate to just slap my 40ps as is on a combo I didn't care much about in terms of build quality.
Plenty of options depending on what you want