You should go 17t on the back if you want to keep the chainring. plenty big enough gear for road riding and loads of skid patches.
And yes, 29er rims, wider and since most are made for disc brakes no machined side walls. Sun ringle make (or atleast did) some nice simple silver 29er box section rims
future plans are higher teethed chainrings and cogs. it is just that this chainring goes well with the hubs.
29er rims? ha, nice one.