My previous AG pool was about the size of yours. I bought a 1/2 hp full-rated inground pump and it was plenty big enough. (Poconos -- one of the other moderators -- picked it out for me when I was in the market for a new one.) It is a Hayward Superpump. It is perfectly fine to use an inground pump on an AG pool.

Since that time, I have replaced my pool and now have a 27 ft. AG and I am still using that same pump and it is working just great with that pool as well.

Just my $0.02.