Here are some links I have found on router options to use that other people might be interested in taking a look at. I am mostly going to cut wood to begin with, but eventually would like to be able to cut or drill 6061 T6 Aluminum in order to make a new build plate for my 3d printer.
I like the idea of using the Dewalt DW660 ($52) which gives you a 1/4″ collet. It is single speed but can be used with a router speed control ($32 from Amazon, $20 from harbor Freight) with some success. It is a bit heavier (3.2lbs) than some of these other options. Is that too heavy for this design?
How well do you think the Proxxon 28512 12-Volt Micromot 50 EF Rotary Tool would work with this design? It is $53 & you also have to buy the $30 power supply to run it.
I already have one of these Mastergrip tools listed below, so I was thinking about trying this to start with since the only cost would be in designing a tool holder to fit it. This weighs 18.6oz.
Here is another inexpensive option that has a flex shaft for it. This is rated at 1amp, so it is probably about the same power rating as the Mastergrip I have.
Speed Control options