*flamesuit on*
I have yet to see a 1J anywhere near the 1000HP mark. Is this because it's a bad motor? No, it's because it doesn't have the aftermarket support of the 7M or 2J and it's fighting an uphill battle in displacement. The 3.4 stroker 2J's make a LOT more power than a normal 2J, you can't argue with the dyno results.
Now, on to the fun stuff of money.
1J's are getting scarce and with that their price is going up. The way to do it right is with a front clip, and it's expensive. There are tons of 1J's out of other cars floating around that require more work to put in the car. Also, hacker harnesses, missing components, weak turbos, and having to extend the wiring harness properly all play into them no longer being worth the money they are fetching on the market.
At this point the 2J N/A-T swap is seriously looking the best bang for the buck. The 2J was used for a rediculously long time in Toyota/Lexus lineup making replacement parts and aftermarket support huge. The motors are cheap, easy to get ahold of, and all the hard work of how to get them in the car and running has been done by other people.
If the car was originally a turbo model I'd say to just build the 7M and be done with it as if it's done right it will give you anotehr 20 years of driving. As it's an N/A you're going to have to replace the ECU and wiring, so going 2J and having a dead relable car with more power and being able to get high quality parts (though they're not cheap) is a huge plus.
The choice is yours and I know people will bash me for saying the 1J has issues, but they do just like any other JDM engine. You can still buy 2J shortblocks from the dealer, so parts availability is great. If I had to do it all over again I would have gone 2J, but at the time I spent all the money on my 7M, there wheren't many people that had done the swap and it was still considered difficult.