Help with my Lighting!

I'm a bit of a noob, but have had my tank for about 2 years, I've been reading and researching quite a bit, but am getting overwhelmed and confused on what lighting would be best for my situation.

I have a 20G Nano, that is roughly 16x16x16, so it's not the largest tank by any means.

I'm currently using PC lighting that are setup under my hood (my tank runs hot in the Summer months, due to the hood I'm assuming (no fan currently).

My ultimate goal is to have an inexpensive setup that will grow coral and allow for more options than PC lighting, but to remain cost-efficient.

I initially and have been looking at the 20" SunPod 150W MH setups as they're complete and are about the maximum I'd want to spend on lighting...$150ish (used).

I'm now realizing that in my small tank, I can run a decent T5 Fixture (same style that will rest on the top of my aquarium and should have less heat compared to my current setup), but am unsure of the amount of actual wattage I'd want to have softies, LPS, and maybe a clam or occasional SPS.

I'm leaning towards T5 as it seems less inexpensive and for my purposes should be sufficient (I don't plan on upgrading my tank anytime soon).  The downside is the majority of the T5 kits are 24", which means I'd have 4" of overhang on each side of my tank...would this look ridiculous/not good?

Very quickly, here are some links to items I've looked at but haven't done a great amount of research on, so maybe you can point me in the right direction...

http://www.marineandreef.com/Nova_Extreme_T5_Aquarium_Lighting_Current_USA_p/rcu01136.htm
http://fishneedit.com/new-light.html
http://fishneedit.com/t5ho-24quot-2-lamp-aquarium-l.html
http://www.petmountain.com/product/light-fixtures/512404/current-usa-nova-extreme-t5ho-x2-10k-460nm-actinic-saltwater.html


Thanks in advance everyone!

Mike-

Thanks for the reply.  As I'm researching more and more, there is actually an 18" model, which is perfect.  The issue from reading on other forums, is that DrsFoster hasn't been shipping the right model and is shipping the previous non-SLR (individual reflectors) models.

If I can get the SLR model in 18", which is obviously a perfect fit, I think this might be the route that I'm going to go.

Here's the actual link for reference:  http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3733+13822+16770&pcatid=16770

My question is this...what kind of coral can I expect to maintain/grow using 40W of T5 lighting?

I think I've come to the conclusion (unless someone can give me a good reason not to go this route) that this is the best for me because it's not expensive...$63.  It will produce less heat than my current PC setup and eliminates the need for my canopy.  Also, the lighting should allow more growth and more options in terms of corals.

Please correct me if I'm off...

Thanks!

from what I have read, mostly on reef central, the advatage to T5's is mostly in having individual reflectors with good bulbs.  the problem with your size constraints is from what I can tell the good fixtures, ATI, Tek, aquactrinics, etc are 24" for the smallest, I think this is mostly because the good bulb's, ie. UVL, ATI, Geisemann do not come in less that 24".   I do not think if would be enough of a upgrade of light to be worth the cost with only 2 bulbs and they are current bulbs which do not have very good PAR numbers.  unless you were going to fit two on your tank? with the 4 bulbs or 80 watts you probably would have enough light to try SPS or a clam up high and it would be an improvement over the PC's.