I juuuuuust had a thread asking about recommendations for 48" spans.
if you're interested.
Looks like the 48"x12" strip light from Spectral Designs
might be worth a look?
A 90 gallon is pretty deep though, so a handful of spot lights might be a helpful addition for specific areas of the tank. I have a 36" tall viv almost exclusively lit with 15W (5x3W) LED spotlights. You can find them on ebay for ridiculously cheap- just have to be careful to get the right color, wattage, base type, and beam angle. More links.
Beam angle is important if you're trying to penetrate to a decent depth. A while ago I found 45° lenses, and haven't seen them since. Lucky for me, the lens component of these lights is easily switched between them. So I can buy whatever angle is availabe and swap out the lenses.
I agree with Kalle- whatever you were using for your reef setup will probably be too intense for the frogs and the plants.