You can gang two single sprockets to run your double roller chain, but the cost will be doubled...

If I end up going that route with smaller countershaft (top sprocket) I think I will head to my local motorcycle shop and match up the splines with what they have in stock, ditch my double chain, and go with a good quality oring chain that I dont have to lube all the time and spray chain lube all over my rear end.....uh I mean my buggys rear end.