Cava welcome,
Imho if choosing between the EP175 and the EP350 I would go with the 350, I don't think you can really have to much sub for a room regardless of the size.
Before you go with either though if you can give us an idea of your room size that would help. And there may be some suggestions for a sub in the EP175 and EP350's price range that may fit your needs better.

A computer once beat me at chess, but it was no match for me at kick boxing.