preamp and amp for B&W N803 speakers

I have a friend that would like suggestions for a solid state amp and tube preamp for B&W N803 speakers, price limit is mid 4K. Used equipment is fine.

thank you

I have had a lot of great listening using BAT electronics with my N801's. Try a VK30 pre and a vk60 or 75 amp. Mix in a lil silver/copper blend cable like Kimber and you are set.
Preamp: Conrad Johnson 16LS or 17LS used; tubes.
Amp: Music Fidelity; solid state.
I wanted to add that in my experience, the BAT combo or another brand of tube pre and solid state amps have the best chance, at your price point, at giving you a warm and liquid sound. I would describe it as being wet. Other pure solid state combos can make the B&W's sound dry an unconvincing. I hope this helps.