BTW, Lotus' motor is actually the US spec (180HP) motor, it got a different exhaust system and Intake
manifold (since the elise is a M/R configuration like the MR2) and the cam switchover (lift point) was smoothed out, and torque falloff was boosted a bit. most of the tuning was from the ECU, and the exhaust was extensively tuned, to the point where it's about as efficient as it gets.
You can't use the exhaust on the celica (the motor is in the front, as opposed to the back of the car like the elise) but I'm pretty sure the ECU should swap in just fine, assuming you have a 6-speed tranny
Toyota was extremely interested in how lotus tuned the ECU, so you can expect toyota to adopt this tuning on future 2ZZ powered cars (so, finding a donor motor and ECU will become easier in time)
JDM and euro motors have more HP because the emissions laws aren't quite the same, and they also are tuned to run on higer octane (usually 98 to 102 octane as opposed to 91-93 octane here in the states) You could swap in a foreign engine, but you will either need to run racing fuel, or you'll need to detune it (swap in a domestic ECU, add a domestic cat-pipe) to run on premium pump gas.
since this is all theoretical, let's determine what part of your motor bit the bullet: If it was the block, just get a fresh short block, and reuse the old head, or, if the head is messed up, buy a new head, rebuild the block, and you're all good. it's usually cheaper to rebuild what you have than to get a all new engine anyways. Check your local salvage yard for donor motors if you're strapped. Crate motors are nice, but real expensive (and I'm sure a Lotus-built crate motor will be astronomical, all lotus parts are)