Your speakers are very good. I had the 8i's myself. I got best results with a Creek 5350SE. You can definitely get a used one in your budget. I had the Naim also and thought it was very overrated. Even though the price was close, the Creek was in a completely different league. I don't think the 50A is made in the UK. The 5350 is. The 5350 phono state option are also very good (given their price).
Recommend an integrated amp, $800-$1000
I'm in the market for an integrated amp, new or used, with a budget of $800 - $1000. I'll be using it (for now) with a pair of Monitor Audio Silver 5i speakers, with the primary source being my Performance SE turntable. I'd like the option to add a sub at some point if needed. I listen mainly to 70's soft rock, jazz, and a little classical and country, all at low to moderate volumes in a converted bedroom. The only ones I've listed to at the dealers are a NAD C326BEE and a Peachtree Decco, and I preferred the NAD. What about Marantz PM8004 or a used Naim Nate 5i-2, or used Creek 50A? Other suggestions that would work well???