Personally I dislike the 3.0 because they are hard to work on.  I guess I am just burned out on doing headgaskes on them.  Durring the week before thanksgiving we had 5 of them torn down in the shop for various reasons (headgaskets, rod through the side of block, valve jobs, cracked heads) and that was what we saw from those in 1 week at the Toyota dealer I work for. 

I'm in the middle of the longest 3rz conversion myself, mainly because of my budget.  If I had the dough though, I would have gone with a 1uz-fe v8 from a lexus with a auto trans.  I love those engines!  I used to work for lexus and saw very few problems with those.  I don't think I have ever seen a bottom end blow up on one - they have 6 bolt mains, aluminum block, DOHC with multi-valve heads.  In fact,  I don't even recall having to pull the heads off of one.