t67

Some standard SOP advice for MA students is to show that you are both critically engaged and teachable. It isn't as important to map out a proposed project as it is to tell a compelling story about you and your academic interests. Most adcomms recognize and maybe even expect your area of interest or project to change. 
You might think of what makes you unique as an applicant and why you're interested in southern lit, and then tell a story through your SOP that highlights your academic and maybe even personal engagement with that kind of literature. What theoretical approaches have you used to help understand that field, and how does your writing sample show these interests, etc.
For example, for my SOP, I started by talking about a lecture that I saw by a famous academic, and how it impacted how I conducted my research from then on. I followed this up with a short discussion of how the classes I've taken and the mentorship I've received from professors has influenced my writing, and then went on to detail the theorists and literary periods that were important to me, and what questions I was interested in answering. I then showed how my writing sample commented on this discussion, and showed what I had gotten from those influences. I was telling a story about my development as an academic, and how I might use that development to make original contributions to the field. Basically, I am critically engaged and teachable, is the story.

It seems like a hard test to prepare for. Really, I think that the best preparation is a good, generalist program in English literature. Like, taking a broad range of classes. There's also a bit of luck involved, in that if you're a Romanticist and there's a lot of Romanticism questions, then you're golden. If not, it's harder to get a good grade. 
I didn't prepare at all, but took the test in the same year that I took Medieval, Romanticism, Theory, 19th-c. American, and Shakespeare grad courses and I got a 75th percentile, which isn't great or anything, but it's better than my 59th percentile the first time I took it after studying and flash carding, but being out of undergrad for four years. YMMV.
There's also some strategy involved, in that you should try to get to the end of the booklet, answering all the questions that you're sure of. I also used the strategy of running through that first round by only answering the questions with short- to medium-length passages to read. I then went back to the beginning and spent the rest of the time considering as many other questions as I could, and I left any answer blank that I couldn't narrow down to 2-3 potentially correct answers, because of the penalty for wrong answers. I think I left like 30 or 40 blank. 

I'm not a Victorianist, but I know that they lost Andrew Miller to JHU a year or so ago, alongside Mary Favret (who is a Romanticist, but still a very significant loss). Obviously it remains a strong department for Victorian Studies, but I imagine they're doing a little bit of rebuilding right now. 

Also, to reiterate what most have said: the Purdue MA cohorts were likely great individual candidates. Going to a school with good mentorship is important, but guarantees nothing. As has already been stated: somebody got in to Yale from Alabama. This is precisely because where you got your MA doesn't really matter. You as an individual candidate is what matters. Rank doesn't matter. Go where you can be reasonably well-supported and happy (it sounds like you would be happy at Alabama or Purdue, but you would have a support system at Alabama, which is not an insignificant consideration), and don't worry about how many students got in to what programs, because ultimately it will be up to you to craft a compelling WS, SOP, and CV and (more importantly) pick the right schools to fit your interests. These are things that schools can't and won't do for you, and they affect where you end up more than anything else. 

Also, to reiterate what most have said: the Purdue MA cohorts were likely great individual candidates. Going to a school with good mentorship is important, but guarantees nothing. As has already been stated: somebody got in to Yale from Alabama. This is precisely because where you got your MA doesn't really matter. You as an individual candidate is what matters. Rank doesn't matter. Go where you can be reasonably well-supported and happy (it sounds like you would be happy at Alabama or Purdue, but you would have a support system at Alabama, which is not an insignificant consideration), and don't worry about how many students got in to what programs, because ultimately it will be up to you to craft a compelling WS, SOP, and CV and (more importantly) pick the right schools to fit your interests. These are things that schools can't and won't do for you, and they affect where you end up more than anything else.