Left-T
A good set of string is phosphor bronze for the ovation. that will give you a very nice crisp acoustic sound. Use medium-light or medium gauge for a deep tone. Ovation can handle any string type as well as any gauge. they are very well built especially at the bridge. D'addario make a good acoustic string and Alexir.

Alan Clark
If this is the sound you want then you should have never bought a applause,

Soarn
I would go for the medium-light gauge. D'Addario is a good choice

Eddie W
I would go for the Elixir.

r
go with D'addario strings