hmm, tough one.. a big block is the easy choice.. it will simply bolt in in a weekend, everything fits, exhaust, accessories, hoses etc. and if you are willing to spend the money on a 572, or somthing like a sonnys 555 it will outperform a naturally aspirated LSx motor hands down.. but its not cheap, and for what you are saying you need.. id say it was almost overkill..
an LSx will just run forever, but you ill have to change everything, or spend some big money to buy everything to just bolt it in.. and it will still not look as good as a BBC..
so my advice would be to buy a 572 or sonnys 555, and if you want wow.. well nothing beats a kinsler stack injected big block... except perhaps a twin turbo rat.. but thats another story
