How much would a rebuild cost? And how long does it take a person to rebuild it?
To just do the short block, bearings, rings, have the crank machined, and have the heads resurfaced, probably 400 - 600 range or higher depending on where you get your parts, and what needs to be reconditioned. I would tear it down to bare block halves and check out the crank first before ordering or buying any parts. Take the crank and rods to the machine shop to have them checked. Rods that get knocked around too much can end up with the big end stretched into an egg shape which means they need to be machined or replaced if stretched far enough.
A 2.2 swap is a viable option if you can't afford to have the car down for a long period of time. You can yank to the 2.5 out saturday and have the 2.2 back in and ready sunday and drive to work monday. This is also a good option if the 2.5 engine is damaged beyond repair.
A rebuild will be at least a week (again depending on what needs to be done at the machine shop, and how long their turn-around is) possibly longer if you haven't done one before. Tools are also a factor. You might want a ring compressor. I've installed pistons without a compressor before. It's much easier with one, but using a ring compressor comes with it's own risks. A cheap compressor could leave you with broken rings, scored pistons, or cylinder wall damage.
Some machine shops will build the bottom end for you for much cheaper than a regular shop would, so you might ask about that if you don't have some of the tools needed for a rebuild.
There are a few good videos on Youtube for how to get the block apart. You might want to check those out.