Indy LA-X vs. Eddy heads

The RHS heads have the same ports regardless of LA or Magnum. The RPMs have changes between them. IMO one of the best parts of the LA-Xs is they use the std LA (cheaper) rocker setups and any LA intake but you get the fast, good working port of the Magnum. They are heavier because they get cast with provisions for either rocker setup, but are machined for LA or Magnum respectively.

Car - FOr the budget I'd think the LA-Xs would be a good addition performance and budget wise as sold by Brian. I say Brian's because the heads are sold bare so any shop's labor counts for a portion of the final performance. He does nice work. Just get a dished piston at zero deck and you're fine. If the budget was another $700 I'd go with Edelbrocks because they'll do everything the LA-Xs will do and be a lot lighter high up an over the nose. Your build looks like a G-machine type general performer build. A mild 408 will cost you close to $6800 pan to carb with RPMs on it.