Thinking outside the box
I see what you are saying. But if eddys, that are just moded stock dezigns are to much money for you. I don't know how a highly moded one with a changed port, that requires a different intake and exhaust are going to be more affordable.
My dad has a set of LS-7 heads on his C5R block. Let me tell you. They are not cheep!
The LS-1 LS-2 and LS-6 heads have the tall port. The bad dog LS-7 heads that are on the 500 HP vetts have rectangle ports. They are short and wide. Why? I don't know. But they are the heads out of all the LS type heads that are the badest. The only better ones I know of are the C5R race heads that are 5000$ or so.