First off, welcome to FTR!

My rather general advice would be to play to your strengths. It seems you have the ability to play NL SnGs, so I would advise playing these. Ultimately, whilst you want and should be looking to improve all the time etc, this is largely to serve the main aim which is to make money!

I could suggest that you play a bit of both, but I think it is better to look to specialise and really try and nail a certain facet of play (e.g. SnGs, NL Ring, Limit Ring) because each has it's own little nuances.

Sorry if this isn't quite the advice you were looking for, but ultimately you need to ask yourself
(a) which form do you enjoy playing the most?
(b) which are you better at?

Once you answer these questions, away you go!

Oh, and please read the BR Management thread.

Post hands, ask questions, enjoy!