Need advice on choice of lighting.

[kadium]

Hi everyone, hoping to get some help and advice from everyone about my choices of lighting fixtures. I'm juggling between 3 different fixtures, and am having a difficult time deciding which one is best for me. These are not my absolute options, I'm open to any recommendations to any lighting fixtures you want to share. So let me start with some specs of my tank and then I'll list the different fixtures.

Tank size: 17.4 Gallon, 24x12x14
Light fixture position: 5-8 inches from top of tank. So possibly after filling 3-4 inches of substrate the distance between the light and substrate will be around 18 inches.
Type of floras: HC, DHG, Flame Moss

My current thoughts on the fixtures. Halide looks much more sleek compared to the other choices, but I have no idea how well they stand compared to t5h0 lighting. I've never used aquaticlife products before, but it seems like it's good value. And regarding the catalina products, I've heard a lot of good praises such as its definite bang for the buck.

Sorry for the long post, I tried to put all the information on one post, for your convenience.


Fixture 1 - Halide @ 140
http://fishneedit.com/150w-metal-hal...ndant-lig.html
Specs:
* Sleek space-saving design ideal for tight spaces.
* Hanging HQI metal halide fixture is only 2-1/2" high.
* Provides high lighting conditions for reef aquariums or plant.
* Features anodized aluminum housing, glass UV lens, high-quality reflector, external ballast, and steel wire hanging suspension system kit to mount the lighting system from the ceiling.
* Double-ended bulb included. (20000K;14000K;6700K are available, 6700K is good for the plant)
* Dimension for the fixture:11-3/4" x 10-1/2" x 2-1/2" high.
* Electronic ballast
* 2 Mounting Leg and Hanging Kit Included.

Fixture 2 - Aquatic Life @$105
http://www.marinedepot.com/AquaticLi...FIT54U-vi.html
DESCRIPTION

T5 HO (high output) light fixture with Roseate and 6,000K lamps.

GENERAL
Adjustable width aquarium frame mounts support fixture above aquarium.
Single power cord makes it easy to mount on the aquarium or suspend from above.
German-made specially angled individual reflectors maximize light by directing it into the aquarium.
Suspension channels allow connection to optional cable for various mounting configurations.
Metal attachments allow optional connection to multiple fixtures.

Fixture 3 - Catalina @ $130
http://www.marinedepot.com/AquaticLi...FIT54U-vi.html
24 inch 2 x 24 T5 HO, 2 cords, 2 switches. Two giant independent german polished aluminum reflectors to put the light in the tank where you need it and no splashguard to block the light.

Comes with hanging brackets installed. Works with the flip up legs only, they are not included and are sold separately.

Width: 8 1/4 inch