I would shy away from epoxy bonded dowels in wood. While epoxy adhesives and pressure injected epoxy can be used to repair wood, I would be more concerned with interface shrinkage and the reduction of shear capacity at that interface. If the dowel will have no tension, then epoxy bonding is probably as good as anything, as properly selected epoxy-to-wood bonds can exceed the wood strength. The Forest Products Laboratory of the US Government has some info on this. Here's a link...
Also, I have uploaded a pdf file on epoxy-wood bond....
The file has more to do with general epoxy-wood bonds, but you might find something useful.
I would use threaded dowels and if you can't find those in the sizes you need, one easy way to solve this is to use long lag bolts with a long, unthreaded shank portion that can be installed to whatever depth you want, then the head can be cut off leaving a smooth dowel.
