You could always consider DIY lighting, that's what I'll be doing...upgrading from 30 watts over a 55 gallon to 112 watts for about $30 using compact fluorescents. I'll have a DIY article up as soon as I get the parts, but I believe there is a similar one up already.
My humble suggestion, is get some reflectors first. Much cheaper than upgrading the entire lighting array.
As for CO2, I have been using Tetra's system. It is just a spray bottle and bubble diffuser. Doesn't cost much, disposable, low maintenance and quite effective.
