Since Neleos will be working on his lab as this year is finished up, I realized I needed to ask a few questions. What size is his lab being built? (I'm guessing it would be size +3 to match the others, but I'm checking first.)
I'm guessing I can pick up Superior construction, superior Equipment and tools due to quality of local crafters. Spacious is always nice for Safety, and is easy to add. I'm guessing there's no Supernatural virtues or flaws just laying around for use (Regio, vis source, faerie ingredients, inexhaustable supplies, et cetera). He would certainly enjoy a gallery, a dedicated building, and a lesser expansion, with some intent to add features when he makes more room.
size is, within reason, by your request. Extra features can certainly be added such as gallery, dedicated building... expansion is an outfittings virtue that would have to be added by you after the initial setup, but you can certainly plan to have space for it. Superior construction, superior equipment and superior tools are given due to covenant craftspeople.
Most of the labs are size +3 and Neleos would probably aim for that. Idyllic Surroundings is just a wonderful bonus, but it's also not appropriate for what he would want, to be honest - he wouldn't want to be far away from the covenant with his lab, he'd prefer to be near his sodales.
Structure Virtues: Dedicated Building, Superior Construction, Gallery, Spacious, Feature: Summoning Circle (+spells)
Outfittings: Superior Tools, Superior Equipment
Any further work he can do as he settles into his lab, of course.