Join Date: Dec 2013
Location: Portland Oregon Metro Area
I have not had very good luck with Porter Cable router bits, especially ones that are 1/4" shaft. I have had great success with Rockler (Rockler.com), Stone Mountain (PtreeUSA.com), CMT and WoodRiver (Woodcraft.com). The 1/2" shaft router bits are preferred. Hopefully, your router can handle 1/2" shaft size router bits.
As Woodnthings stated, you will need some support to hand route the rabbet around the inside edge. One method that I use is to build a sled that is wider than your box by 6" inches. Mount your router in the sled and then you can use the sled to keep the router vertical. Google search "router sled" and you can find lots of references for a router sled. Most of them are for flattening large slabs, but the concept works for rabbeting edges on boxes also.
I use my router sled to flush trim cabinets that I have glued strips of hardwood on to cover the plywood edges. The flush trimming trims the hardwood trim to match the plywood side.
Your boxes look small enough to handle on a router table, if you have one. If you don't, maybe it is time to make your own router table.