50,000 BTU's? Yeesh. That's kinda small. Bringing 10 gallons to boil with only 50,000 BTU's would definitely take you a while. If I were you, I'd keep looking.
I've got a 180k burner and a 210k burner for my 10 gallon batches. The 210 is a bit of overkill, but the 180 is nice.