Budget Integrated for 2nd system

I'm looking for recommendations for an integrated amplifier for my 2nd system in a room that's 12'x 13' x 8' in size.

I have the Kef LS50 speakers, Rega RP3 turntable with Ortofon 2M Blue, Musical Fidelity V-LPS II phono amp and play lossless flac files from my PC using JRiver and the Meridian Explorer DAC.

My current amp is an 8 year old Harman/Kardon AVR 325 receiver, but it doesn't drive the LS50s as well as I'd like and has an annoyingly noisy cooling fan that turns on and off when the unit is on for 15 minutes or longer.

My budget is approximately $500 and I enjoy most types of music, particularly rock and jazz.

So far the best possibilities I've found new are the Marantz PM5004 and NAD 326. Has anyone used either of those with the LS50s?

Any others I should consider?

Thanks for your time.