If you are doing a lot of RC models then you may want to think of a 1-6.0mm set in 0.1 increments, I use this most of teh time for all my imperial and metric tapping drills.
Having just bought a set of the little hoggers I don't see me using them that much, a small dia flycutter seems to work better though I have not tried them on brass yet which may respond better to the negative rake. And my 40mm indexable endmill will be what I reach for more than the little hoggers.
I really like my electronic touchpoint edge finder and now only use the other types when I can't get the electric one into a tight space.
A boring head is useful for larger holes in items that are too big to bore on teh lathe, a few carbide bars for this won't go amiss
A nice set of Tee handle hex and torx keys is something else useful especially the small T7 & T8 ones for indexable tooling, easier than the keys supplied. Eklind do good ones, Again from J&L.
Vernier height gauge, vee blocks, 1-2-3 blocks, angle plates are all worth having.
Jason