First you need to consider your tank. A 46 gal bow front is about 36 x 16 x 22. If your going to go with pendant fixtures like the EcoTec or AI, to get an even light across the tank, you are going to need two LED fixtures. If your going with strip type LED fixtures you usually need a lot of strips, because these tend to use much lower power LED.
When you say you want to control them externally, do you mean they have their own controller, or do you want to control them using a general controller such as a Neptune Apex?
I have to disagree with
@nanoreefing4fun here. Steve's LEDs are a good product, but if you look at their web pages, they are more geared to retrofits. This is what makes them so good at LED system for the RSM 130 and 150, and other similar systems. I don't think they would be the best choice for other systems.
As you have seen, the Ecotech Radions are expensive, but they do all the tricks. Consider that they output a lot more light compared to the others your looking at. More light means it cost more dollars.
The AI Prime is less expensive, but puts out less light and does similar tricks. This may not be bad, because you'll need two fixtures as explained above. It comes down to what you want to keep in the tank.
For the Current usa and orphek the evaluation is similar, less features or less light gives lower cost.
Like anything else, this all comes down to how much are you willing to spend verses the amount of light you want and the features you want. Since I have AI Hydra 52's on my 125 gal reef and like them a lot, I'd tend to pick the AI Prime, but lighting is the most subjective reef subject in the hobby. You wouldn't go too far wrong with any of the lighting your looking at. As usual, I recommend buying top quality in this area.
