Like Sujo mentioned above, the Hydra 26HD would be the better choice. Though in my opinion, not the Hydra 52HD.
I run a Reefer 170 which is basically a Fusion 40 without the all-in-one.
The Hydra 52HD is a great light for deeper tanks. Though, if you're going to the Hydra route, it would be best to start with just one Hydra 26HD and eventually add a second. These are more powerful than half of a H52HD. Also quite reasonably priced, especially if you find them used.
The Prime is a great light, for a smaller tank. That being said, I've heard one-too many times of people throwing an AI Prime HD over a R170 or F40 and having regrets or having to add a second. Though with the Prime, you're pushing 13 LEDS opposed to the H26HD, where you're pushing 26. Yes, thats simply because you're adding a second puck. HOWEVER, this is going to truly help balance out PAR spread. The Prime is registered at 30-50 PAR at 23" apposed to the H26HD at 100-130 PAR at the exact same distance.
My R170 is SPS dominant with SPS growing quite quickly. I forsure will be adding another H26HD sometime in the next few months. Though if you're not SPS dominant, 1 H26HD would be sufficient enough.
Side note; if you do go with the H26HD or anything of the HD series, PM me. I'll send you over a profile a few of us on here are using. It's Ecotech Marine's SPS AB+ mock profile for Hydras and its working amazing!
Cheers!