Just my opinion, but from a career standpoint, you need to keep in mind where you want to do fellowship. If you want to match at a big time Heme Onc fellowship (meaning a top 5-top 10 program), you need to go to a top flight residency, which in your case would be UAB or WashU. Indiana would give you a lot of options too, but primarily in the midwest. SLU is a fine program, you just have better ones on your list. So I would think about your priorities; if being at one of the best heme onc research centers in the country is your primary goal, then SLU shouldnt be as high. If your primary goal is being near your SO, I would say rank SLU higher. One thing I wish I had known when applying for IM residency (i just matched fellowship this year), is that fellowship match is very regional, so I would keep in mind where you want to do fellowship before picking a residency. For example, (and im just making this up), if you are from the east coast, you might not want to do residency at Scripps if you want go back to the east coast for fellowship.
However, from a personal standpoint, you have to do what you have to do to keep your SO happy. UAB is an awesome program, but UAB is pretty much all there is in Birmingham and Alabama, so if you match there, you sort of pigeonhole your SO into matching in Birmingham. And they may be able to match there, but if they don't, you are living apart for 3-4 years. SLU is not as prestigious as those other programs, but there are more programs in St Louis than Birmingham which gives your SO more options, and being an MD/Phd, if you really kick butt in research during residiency or if you are a chief, you will still be a strong fellowship candidate coming from SLU.