Wow this is a tough one. $20K seems like a lot but it really isn’t. I’ve gotten used to working the way I do with my regular set of tools.
I’d probably buy a Neotek series II or a Trident 65. An MCI JH24 would be a better idea than my 3M M79 because service issues would be less costly. AT make a bunch of cost effective and good sounding mics. I’d get an ATM 25 and an ATM23HE, a pair of 4050s and a pair of pro 37Rs, and maybe a 4047. I’d try to get some 421s. The EV 408 and 468 can be had cheap and sound great. The same with the Audix D2. A couple of SM57s I guess, though I’d rather have other things, sometimes a 57 is right. Beyer M88’s are also quite useful.
I think I’d need at least one outboard pre. Great River is wonderful, but if the budget were a problem I’d get an RNP. I would get at least two RNCs while I was at it. A Mindprint T-comp makes many different sounds, but is a bit hard to come by used.
For effects, I’d get a TC M-one and a D-two. Maybe a SPX something and a Lexi something. Those Line 6 delay and mod things look cool too.
Though they get dogged a lot I’d get a set of HR 824s. I’m familiar with them and actually like them. We’d need to add a headphone amp and phones, stands and lot’s of cabling to the mix as well.
I’d do 98% of my shopping on the used market. That way I could "maximize my buying dollar."
OH Shit, I forgot a mixdown deck.