Like stated above, the most important thing is to check for rust in the lower control arm mount area even if the car is down South because some of those cars are from up north.
A 3 cylinder 5 speed 1998-2000 Chevy Metro with A/C should not be that hard to find. Getting a 4 door or a Hatchback is up to you, but I prefer the hatchback look and the usable room inside. I do not think you will find cruise on a Metro factory installed. I never seen one yet, but have seen aftermarket units installed. The seats on older models were horrible, but newer seats from the 1995+ era are much better.
If you drive the mountains, then you can expect the 3 cylinder to be somewhat weak especially if the A/C is on, but if it's running properly, then you should not have too much trouble. It's a commuter car and that's all.
If you get one and want more power, you can install a 10 degree advance cam gear available from
3Tech and this will boost the power. There are also exhaust upgrades you can do also.
Good luck on your search!