I use glass tops on all my aquariums, while it does block some of the light (especially if you let them get overly dirty) I think the benefits from keeping the fish in and limiting evaporation are well worth it.
What ferts you need depends on how much light you put over the aquarium. Since you're talking CO2, I suspect this will be a high light setup. As a result you'll want a good trace supplement (CSM+B, Flourish "Comprehensive", or Tropica Plant Nutrition) along with Nitrate (KNO3), Phosphate (KH2PO4), and Potassium (K2SO4). Dry ferts are definately the most economical way to fertilizer your aquarium.
There is such a thing is liquid CO2, but you get it in a pressurized cylinder and it turns to gas as it's released from the cyclinder. Not quite what you were asking though was it? CO2 injection is actually providing carbon, and while there isn't a liquid CO2 that you dose by the ml there is Flourish Excel. You do have to be careful which plants you use it with as Anacharis, Vals, and Riccia are know to melt when they come in contact with Flourish Excel. It's a great option for smaller aquariums, but becomes very expensive in large aquariums.
Coralife and Current both make really good light fixtures. Once you figure out for sure which aquarium you're going to get, we can make recommendations for specific models.
As far as the aquarium goes, I'd recommend trying to get a breeder. These are shallower top to bottom and deeper front to back which makes them much easier to light and aquascape.