Hi,
I have the same tank with the same light unit, and i also had 2 marine white and 2 blue moons as i changed my vision 260 from a marine to freshwater almost a year ago. Coincidence eh? Good minds, good minds..........
Anyway, i looked into the exact same problem as you and decided that the Arcadia Freshwater tubes would be best, only to find that you can't get the freshwater tubes for that light unit. Plant pros it is, then...............
The plant pros are good, but you are right, they aren't as white. I don't mind because my tank is quite heavily planted and they're god for the plants, although 4 Plant Pros came to about £85. Ouch!
Definitely change your marine bulbs. I am led to believe that they will encourage algae in your tank. Thats why i changed mine.
Also, a word of warning. The plant pros are 54w each. Using 4 of those is a whole load of light over your tank. If you decide to do so, i'd highly recommend that you set up stable CO2 and ferts too, or you're heading for algae central. If you don't want to spend the money to do that, maybe only use 2 tubes.
You can get an idea of what light the plant pros produce from my tank journal in my sig below, if thats any help. You'll see the light from the marine tubes in the beginning of the thread and i changed to plant pros half way through, so it'll give you a good idea.
Hope that helps you a bit.
Cheers
BTT