That fixture will work for low light, as long as it's suspended *directly* above the top of the tank. You will really need every bit of light it can provide. It cannot provide medium, or even medium-low light, which limits the selection of plants. Since experimentation and growing an assortment of plants (and algae) are in your objectives, you might find that fixture limiting; at least long-term.
You also sent me a visitor message. The bulb you're looking at to pair with that fixture is cool white (4100K), which won't look very attractive or grow plants as well as bulbs at 5000K or higher. 6500K is a good starting point, and Lowe's should have those too, in stock for the same price.
Finally, you mentioned lush carpeting plants. Since they live at the bottom of the tank which receives the least light, they have a tendency to grow upwards to reach better light rather than spreading out. Growing a carpet in a low light tank is particularly challenging. I'd recommend at least medium light if you want a fair shot at that.
Unless you're willing to go over initial budget on a better light that can be suspended to provide a variety of lighting levels, or don't mind possibly purchasing another light in a few months as you get a better idea of your objectives, the 10G incandescent strips are probably your best bet for now; especially since you already have them. I'm seven years into the hobby with six tanks, and still use those hoods on a couple of my tanks; changing the bulbs or layout as my needs change. The flexibility can't be beat.
Thanks for the input! I'm glad I still haven't purchased anything, didn't think the t8 two tube fixture would be such a soft light...!
Leaning more towards a T5 now.... It seems like such a deep tank, and eventually achieving a lush carpet of some plant or another would be very rewarding. I feel I'll have more room to play around, can raise and lower the tube as needed, and if I'm not using it for a planted tank I can use it to grow some other cool plant...!
Can pick this up for $28.... Thoughts...?
Otherwise this is the strip that I have...? It takes 18" tubes, but I don't know if it will take a 6500k tube (edit: looks like it will, http://www.google.com/products/catal...d=0CGwQ8wIwAg)
? Currently has a 'F15T8 Eclipse Natural Daylight' tube. My other strip is a ZooMed T5 12 Watt Tropical Bulb (it's a lot smaller than it sounds)...! Would they work...?