PG:

The most important thing is to make sure the filter is big enough for the pump.

I cannot imagine you needing anything bigger than 1/2 hp--even a 1/2 hp up-rated (for AG pools) should be EASILY adequate, and a 1/3 hp just as good.

You can call the pool pump companies and ask for their advice on their products. For example, Hayward makes an above-ground 1/2 hp and an above-ground 2 speed 1 hp.

They also make a small sand filter and pump combo (the S144) that sells for about $375. That might be ideal.