So leaning toward the Nainiat littlebox for the stealth side and maybe a V3 for the open mic side.
Still open for suggestions.
That sounds like a good plan to me. I ran the V3 for 6-7 years and thought it was a great preamp/ADC. I recently picked up a Naiant littlebox and after having run it for a few times think it is a fantastic pre for the money and the size/functionality, and really a very good preamp option regardless of the money.
I've done a comp of it with the V3, and the littlebox fared very well. At least on that outing, the LB sounded as good or better than the V3. I've replaced my V3 with a PSP2 which is a great box if you can find it, but that's a pretty difficult search.
I'd get the LB once Jon starts making them again in October and try it awhile. You might find you won't want a V3 for open. Personally, I think that having the PSP2 (transformer) preamp for a bit more color and a LB for a more transparent sound more than suits my needs -- no knock to the V3, which I loved when I had it.