If you are paying cash out of pocket I'd go with Seminole... if you are using 9/11 GI bill then I'd go with HP and 737 type rating. It is a crap shoot when you are doing the practical with an outfit like All ATPs and a FAA examiner... HP gives you more structure.
Regarding application timeline... i'd put in my application 12 months out from terminal leave... and would make sure you have your ATP before you apply...
Just one man's recommendation!