Umm...So if your 500w panels are really 9.38A x 33.05V = 310.009w, then they are 500w panels how?
Silfab is fine.
If you can get those 310w panels for a competitive price, I'd say go for it.
It all depends on the price. Of course these are not high wattage panels, but if you are not short on space and get these for cheap, then why not? Siflab makes good panels and have been around for a while.