How Would I Go About Researching '000s of KWs?

Hey chaps,

I have a project that covers a LOT of keywords, all of which can convert.

My 'simple' question is, what method should I adopt to convert a list of '000s of KW's to say 100s of KWs for closer KW targeting analysis?

All the best

Please do let us know the competition of those keywords too.
Few keywords get ranked with proper on page optimization and good content too

Anyone?