I don't think I'd go thru the rebuild myself... now maybe if I were as inclined, mechanically, as some of the other posters I've seen here, I might attempt the rebuild. The downside of that would be I'd still be dealing with a naturally aspired engine on a 4 speed automatic transmission. :\
I think you might not be using the best search queries for what you're lookin for. If you want a replacement or a swap, try "JDM (engine code) swap" IE: "JDM 7mgte swap". If you're more lookin at doin the engine and tranny, as it sounds you are, you probably want to look for front clips. This is essentially everything from the firewall forward (as I had it described to me), sometimes including the front portion of the chassis/body. Can easily find that in a search for "(Engine code) Front Clip". IE: "7mgte Front Clip".
Just a quickie, I've found a couple links, tho I'm not sure of the reputability of the sites.
JDM Front Clips (Looks like the 7m doesn't have a tranny, only the jz's)
JDM Front Clips, Engines and/or Trannies (Website looks better put together)