My 1999 Camry's a 5 sp stick w/seized up engine.

When it comes to engine swaps as DIY projects, this is not a beginner's job. I could probably do it, but I know a bit about working on engines. I'm also in the DIY minority, and that's okay; not knowing is fine. Not everyone knows the common tricks to doing an engine swap because of how much work it is.

It isn't particularly hard to do this, but there will be many connectors on the engine; the main setback is the disassembly needed (very often, you have to remove the front bumper and headlights for clearance reasons. On ALL FWD cars, you need to remove the front axle, as this takes the place of a driveshaft in a RWD/AWD/4WD car). Pure FWD drivetrains all have transverse mount trannies by design that come out as a pair.

When you get an engine, you probably want to source it from Japan or a junkyard that pulls and tests it before selling it. You want one with the fewest possible miles (which will be hard given the car's age). The engines from Japan tend to have fewer miles than they do in the US when it comes to Toyotas, which, as long as you can transfer things like the manifold and US sensors, will not be an issue, especially with the same engine code. In addition to this, you will need an engine stand to hold the engine while you remove the trans and then move it to the new engine. You also need an engine hoist to get it out of the car.

If you are up to doing it yourself (pulling it and installing it) and can't find a good bare engine, you can probably get a junk car with rear-end wreck damage to get the engine and transfer your manual trans to the new engine (legally you should test it in a parking lot, but I know people stick their plates on it and pray they don't get caught by the police when test-driving the donor car). There will likely be no issues if it bolts up, even if the donor engine/car has an automatic trans and you could not just buy the engine. The TCM tends to be a dedicated module or part of the ECU programming, but I would double-check that to be sure to see if you have to swap anything else other than the trans since manual cars aren't as commonplace (in this case, these Toyota ECUs are WORM, so you can't reprogram them to take an auto trans anyway; you'd need the ECU from the donor and the ability to program the immobilizer to the replacement ECU). Chances are strong that if the manual trans car you have uses the same engine as the common auto trans cars, it will not be an issue.