Streamer+R2R dac+True balanced Class A preamp all-in-one?

Ibid. 

This manufacturer called Gustard (that you suggested) has gotten 2/3rds of the way there with the integrated streamer+ R2R dac for 1650 USD (8350 under budget). But, all of a sudden, integrating a higher quality class A preamp into that unit would suddenly never fit under or equal to 10k? My budget is too weak for that to happen somehow? Tell me about that fact and reality a bit more

Okay, it’s clear to me now that you don’t know what you’re doing. First, many if not most good preamps operate in Class A, so just stop with that. Second, you won’t find any R2R DACs incorporating a good streamer, so stop with that. Last, if you combine a good and fully-balanced preamp with the Gustard, its streaming section will be a big bottleneck to performance compared to the likes of an Innuos, Lumin, Aurender, etc. that you should be looking at, so stop with that. I’ve had enough here. I’m out. Good luck with this mess guys. Or maybe someone else can finally get through to him here.

I am of the belief that a integrated streamer+dac+preamp unit eliminating unnecessary cabling and non-merging of different design ethos’ from different manufacturers can churn out better in execution.

I’m sorry, but at your $10k price level I completely disagree with this logic even leaving out the fact that you’re not gonna find the unicorn you’re looking for in one box unless you’re willing to relax at least one or two of your stated requirements. @pavel_dosko is absolutely correct that you should be looking at separates, and I’m sure others here will agree. What you say about built-in synergy and eliminating cables makes some sense but only up to a point and you’ve way passed that point. You won’t find what you’re looking for because it doesn’t yet exist so might as well resolve yourself that you’re gonna need at least two if not three boxes. Time to face facts and reality man. Don’t mean to be harsh here, just maybe a voice of reason FWIW.

This is a pretty tough ask as most R2R DACs tend to be just DACs.  The only thing I can think of is the Gustard R26, but it’s well below your price target and not sure if the preamp section is fully balanced or Class A.  Is there a reason you want/need everything in one box?  Quality aside, it’s obviously also extremely limiting in options.