I just purchased a Finnex 24" Fugeray for my 60-P (~17 gallons). It's been on there a week, and I'm really pleased with it. As far as how well it'll grow plants, I'll have to wait and see (but others have had great success, that's why I picked it).
I chose the Fugeray over the Ray II because I wanted lower lighting. Being honest with myself, I knew that I wouldn't be able to truly take care of a high light tank, so I went with something that, if I were to run out of CO2 for a few days or few weeks, it wouldn't make my tank into an algae oasis. It seemed to me that the 24" Ray II over a 14" tall tank would have been a high maintenance, very high light tank.
As far as the AH Supply lights...they look awesome and it's a great concept and being able to retrofit is an exciting proposition. However, I'd probably rather spend just a few more bucks an get a Finnex fixture because of the sleek design. 20W 22" AH Supply retro is $84. Finnex 20W 24" is $95. That $11 is really worth it. The sleek nature of the finnex really did wonders for my 60-P. I'm very happy to be rid of the (comparably) HUGE Coralife Aqualight that was on there before.