best budget amp/preamp for B&W 805 D3s

you kind people helped me along the way. here is another question. I am happy with my setup but can’t help but think forward. Have an old Rotel RA 1070 that now powers my new 805s. I use, per your suggestion, DAC (Shiit Modi) to stream Tidal from my Mac. Sound is great but gets a bit choked up (crowded?) when the volume is turned up loud. my question: I have only $1k budget for a new integrated amp. 1) In that budget is there a significantly better amp or amp/preamp combo? 2) Should I wait until I have more $$$ to buy? 3) what budget integrated amps (amp/prem) go well with 805s (other than Rotels)? 
I don’t mind getting used equipment. Please, give me suggestions also for budget amp/preamp combos.
I very much appreciate your willingness to help. I am new at this and not an engineer.