Hi,
The light fixture looks pretty good, but it depends on your setup and what kind of plants you are planning on growing, and how much cash you have to spend.
First off, there are a lot of posts and info on the forum to give you a wealth of information about lighting. If you haven't done so already, READ THEM!
(Not referring to you specifically at this time, but it is amazing how people don't bother to read the information on this forum, and keep asking the same questions over and over. Some bright and informed people took a lot of time to post some great information, but it is often overlooked as people don't want to bother to look around and do a little research.)
Now , back to your situation specifically....
the fixture you are looking at seems pretty good, however you could go with a 4 lamp fixture if you have the money. Also, as I said it depends on what you are planning on growing. Some Neps will grow big enough to reach up towards the lamps, but a bunch of sundew sitting at the bottom of the tank will be a foot or more away from the lamps. In that case, you will be losing a lot of light!
Light radiates from from the lamps, and it is important to make use of as much light as we can.
See my diagram I made to illustrate, how the angle of radiance is wasted when we place our plants further away from the lamps/light source:
Larger distance:
Shorter Distance makes use of more of the angle of radiance:
One last thing, remember that the more light, the more energy from the lamp,
and that part of that energy is going to be in the form of heat!
You don't want to cook your plants!
Good Luck!
Paul