Why are you so apparently, "Stuck" on a, "Balanced Only", set-up in your rig?
I kind of get "get-it", as I went through what I shall a, "Phase" doing basically the same thing at one point!
But that was years ago and I got over it as nearly all of us do.
"Yes", "XLR cabling" has it benefits. But limiting yourself to JUST XLR in/out config.?
That is WAY, way, way more detrimental to your possible choices at this point in your rig than if you didn't worry so much about that right now. "OR, ever even". As the XLR's benefits "Can" be, "Negligible" at best, most of the time.
I have many amps. Many "Great", amps. This according to friends, reviews, and reputation. And also my own humble opinion. And most of them? Are in fact "RCA, only", in/out. So I would simply advise you to,
"Quit that"!
Having said all that, it just occurred to me....
I do have a "Threshold, T-100", amp. With both the XLR and RCA inputs. "Factory mods". That both sounds amazing, and has been recently serviced. And is also for sale. AND it is within your budget. "In case you are interested". Also a "Threshold A400", with the XLR Mod. But that amp is above your price-point.
And if you wanted to up that game? Up it, "Quite", a bit actually??
I also have a pair of the "Manley Labs", "Snapper"", mono-blocks with both the the XLR/RCA's. Which are a little bit over your budget. But, the "Manley Labs", "Mahi", mono-blocks which I have? Those would be at the top of your price-point. And they would work just as well as the, "Snapper's".
BUT, You would in fact be restricted to the RCA inputs only!
Yes, I have the "Manley's" above to sell, but I really only mentioned them to make my point above.
Hee hee, I really don't "Want", to sell them at this time.....
But the Threshold T-100?
Yes, definitely, It needs a good home!
One more point, Just in case...
You do realize that cabling is available which has both the XLR on one end and RCA on the other, which does in fact exhibit the same benefits as the "XLR only ", cabling right? "
Any noise is still canceled and any of the noise/distortions thus relieved are shunted back to the XLR device and done away with.
Just always use a quality cable!
Regardless, Good Luck!!