I just started with mine, but I was in the same boat, looking to outfit with the best stuff I could find.
A good selection of end mills with spares is essential. Lots of places to get those, but you can’t go wrong with the C3D ones. 90 and 60 v-bit, .25 and .125 EM, .125 BN. I also picked up a 3/4" bottom clearing bit which made surfacing my wasteboard quick and easy.
I have the suckit dustboot and I consider it to be essential as well. The only problem I ran into was using it with a 2.5" hose. The dust boot really should be an inch or two longer to give clearance to the router mounting plate. Or you have to use a smooth sided hose. I have a standard dust collector hose with ridges on the outside and the router plate hooked into it causing the belt to slip. I now have a 1.25" hose piece from the dustboot to clear the mount, then the adapter for the 2.5" hose above that. I’m not totally pleased with how it looks, but it works. I’ll probably switch over to a rigid hose instead.
I don’t have a touchplate, but I would have ordered one had it been available. However, I haven’t found a need for the touchplate, zeroing the unit to my material hasn’t been an issue. I haven’t done anything requiring the precision of the touchplate either. I’ve been eyeballing the X-Y location and using a post-it note to set the Z. When I’m doing a full thickness cut, I don’t even bother to set the Z correctly the first time. I just set it to a little above the material, let it do it’s thing, then use my caliper to measure the difference between the distance to the wasteboard and the distance the cutter went on the first pass. Then I drop my Z that amount and rezero. Perfect depth cuts every time.
I have the t-track and clamp set, but I’m currently not using it. I was impatient and wanted to get a feel for the machine before installing it, so just attached a piece of 3/4" OSB to the machine and surfaced it. So far it’s working great and the tape/CA glue hold down method works like a charm. The only issue I have with that method is during full depth cuts the bit can pick up some of the tape glue and it gets all over your material.
Honestly, while it’s nice to have everything you could ever want starting out, getting to know your machine first is probably the best idea. You may find, as I did, that not every accessory is needed right out of the gate.