No you can't do the 65w thing. It won't work.
You ought to try to repair the one you have. Lighting fixtures are usually pretty simple. Take it apart and check all the connections. It may be the ballast, but those are usually pretty "available."
Most decent LFSs (dedicated LFSs, not petsmarts, etc) will be able to work on them to some extent too if you are not comfortable with the electrical aspects.