Offna Hyper 7 nylon spur gear?

I'm running a Feigao 10L in my Hyper 7 with steel Mod-1 pinions. The spur gear is steel also which, I have read, is bad for reception and the two gears together make nice little metal particles in the chassis (yes, the mess is correct).
Where can I get a nylon spur gear for the Hyper 7? I see that Monster sells one, but I can't tell if it will work with the stock center diff and it is not in stock.

Can anyone help me out?

Thanks,

Chris