for the time being slam a plastic mat in the door and drape it over the outside of the window (a towel will work, but isn't impermeable and will let some moisture into your car).
i swapped a '90 motor into my '93 and it works like a charm, so any 90-94 motor should work - check out a junkyard for the motor itself, if you buy it through a supplier you're looking at $lots (my mechanic quoted me something like 6 or 7 hundred) There are guides on LexLS for removing the door panel, which is easy if you have patience, and the window motor itself is a simple mechanism that makes for an easy DIY swap if you're analytical. It took me longer to get the door panel off than to replace the motor.
One very important thing to note is that under your door panel there's a plastic insulation sheet that has a black tar-like substance holding it on. It will re-stick, but be very careful not to let any of it contact the rod that controls your door locks, otherwise after you reinstall the door panel the rod will drag and your lock will stick. Your power locks won't have the power to completely lock or unlock the car and the lever/button/whatever will stick halfway between lock/unlock unless you force it by hand.
