1) the reasons given aren't enough to choose. You need to do In-Depth research ie ratios, stats, trouble shooting etc. In order to really know what you want; you have to know what you are getting in to and whether or not it will satisfy you.
2)I would rule out the possibility of swapping a 2jz. If it will take you until next summer to buy either, how do you plan to pull of all the fabrication and installation monetarily? given your situation it would most likely be a long long long build. which isn't exciting and can end your enthusiasm due to how much time you will spend on waiting to finish. The main attraction these are both given aren't for their power, it is for their: balance, suspension, and handling. Placing a 2jz would eliminate the complete character of either car. At best it can be a dd/track car, but will never be the ae everyone loves. It's a great concept, but the "stuff" that makes those cars "it" will be gone. There are many other swaps that you can do instead of that engine and you would get greater results and keep the character. Maybe not 1000hp but with certain engines, you can get to 30-500 hp and that is more than enough power for these lightweights.