If the extra money isn't an issue get the 73 type because if you don't have civilian part 25 aircraft experience its invaluable.

What is hilarious, but upon reflection is actually sad, is that "other airlines than SWA" may feel defensive or wary of you if you show-up for a interview with a 737 type. What that says about them is them thinking "we know SWA is better a place to be a professional passenger airline pilot". And going by their reasoning they are so, um, ashamed, they probably won't hire you. Just one of the hundreds of fabulous nuggets of commercial aviation rationality you're going to experience once you're out of the military.