What is the best coating for a rubber roof?

Hello all! I am not only new to this site but I'm also a relatively new RV owner and full timer! I have a 2003 Keystone Montana 5th wheel that is 32' long. I was in the process to start re-sealing the roof with dicor self leveling lap sealant, when I started noticing white stuff chipping off my rubber roof revealing black underneath in a few areas. It is cracked and chalky also. I even found a small whole in the white coating that i cod pull up and put my finger under and see black underneath as well. It needs to be completley re-sealed because the previous owner did a terrible job at maintaining it. I want to recoat and seal the whole thing and was looking at RV Roof Armor but it's pretty expensive and I would have to finance it somehow. I like the idea of someone more qualified doing it and the lifetime warranty that comes with it. I was hoping someone on here could give me a bit of guidance and advise on any DIY coating systems or products. If I can save some money I would like to but I also understand you get what you pay for. I'm gonna probably be in this thing for a year or two before we get serious about buying a house. Any advise would be greatly appreciated! When I figure out how to upload pictures I will post them. Thanks for reading!