JacMac -
I agree that with $ removed from the equation the CHI's or AFD's are a no brainer. I'm a bit tight on cash now, so the plan is to use these 4V's for a season or two, then swap over to the Aussie Aluminum CHI's or AFD's later. The only way I would keep the iron heads is if performance is sufficient. Then again, the plan is for about 550 - 600 HP with the iron heads, so they may be lasting a bit longer than I thought!
I've gotten a lot of good advice here. If the seats were cheap it would be a no brainer, but they're going to be over $300, which isn't exactly cheap in the big picture of building these heads. They are the single biggest cost of the head build. Given the low use and possible temporary nature of these heads I'm very tempted to skip the seats, especially after what you just told me about reducing the valve area.
Is anyone out there actually running without the hardened seats, and have you seen an adverse effect? I doubt that it would actually have to be a Cleveland, I would think cast iron Windsor's or FE's would be affected by this as well. Anyone?