How big can I go while keeping the same light?

[OCDP]

Hmm, well I am not too sure of the height of my 20g. I do know it's just a standard 20g, but I still don't know the dimensions The height.. I'd like to make a little higher than what I have now.. maybe a few inches higher.. that's about it.

Funds are not so much an issue if I can do this without the light upgrade haha. I just wanted to keep most of what I have for the most part...

Can you guys help me out in deciding where to go to get the cube built? Quality and price.. and does anyone know how much the cost goes up if I wanted to use starfire on the front pane??

Sorry for all the questions