Great advice, I read up on the bases a while ago and how they are made but all I really remember is to get the sintered.
I think that's what I'll do, rent all the ones I like and were recommended and see what I like best.
In terms of sizing, I'm under the impression I should riding as low as a 151 for park and sayyy I dunno 159 for pow? I'm 152 lbs. I prefer good control so I'm thinking maybe a 153/154 would be a good in between?
You pretty much got it. Every board and board manufacturer will be slightly different on sizing, but overall that's your window.
I weigh 145ish lbs and I prefer 152cm boards for freestyle all-mountain just for comparison, give or take a cm depending on the board.