I'v been running Radions for several years, and I like them.
That being said, a Radion Pro is over kill for that tank, and a single XR30 would leave the edges of the tank under lit.
If you were going to go with Radions, I would try two XR15's and spread them out to cover more of the tank.
I did not find the reeflink too difficult to figure out. There is a little confusion, but I was able to figure it out.
A Reeflink is NOT necessary to run Radions. But it does make it easier.
Honestly, I think you may be best served by the ATI fixture.