2.7 rebuild done properly costs a nice-sized pile of cash. I spent 7k this spring doing one with my own labor, 8k including the big oil cooler setup. The 2.4 sounds interesting - I've got a built 2.4 that is a ton of fun. What're the specs on the one you're looking at?
Then of course there's big-bore, aluminum cased stuff
. You want something that'll breathe at altitude...y'know, big ports...