CNC Router Tooling for a cnc new-be

I am wanting to do some line drawings on wood and plastic.
My question deals with tooling. (Cutting Bits)
Where do I get them and what should I look for in a good bit.

My router has a 1/4" collet cut into the shaft. Just insert 1/4"
shanked bit and tighten nut to secure. I would like to cut 1/8"
lines if that makes since. Do they make a step down collet for
this type of tool? It is a Ryobi 3/4 hp router.

I just finished adding a floating pen to my Z axis and I would like to
test my G code having it mark the material. Then if all looks well.
I remove the pen setup and install the router and then reset and
have the machine cut the same path. I can make the swap in less
than 2 minutes so its not a big job.

Thanks in advance for any and all the help!

Troy

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