Given the choice, I'd choose the Marantz combo. Warm but not mushy, with great details. I'd also look into Rega Mira for amping; surprising dynamics, clarity & musicality. Also some of the entry level Cambridge Audios. Both Rega & CA make some of the most well regarded CDPs, too, so they'd make an attractive one-company approach. Go audition these & let us know what you think... good luck!

Welcome Niko- I have a suite of Wharfedales (Pacific Evo's and Opus) that are similar to your Diamond 9.2's. A Marantz 7001 Universal Player really opened up the top end and added detail and air. The Wharf's have that typical English warmish sound, so the marantz really helped. In a small room like that (been there) you can/must play with speaker placement to avoid a boomy bass response, but it can be done. Have fun...

I'd also look at the Cambridge Audio Azur 640A v2 intergrated amplifier and the Cambridge Audio Azur 640C v2 CD player, and the Music Hall A25.2 intergrated amplifier and the Music Hall CD25.2 CD player.

I'd also look at speaker placement per Cardas<<=click here and acoustic panels at the first and second reflection points and bass traps in the corners<<=click here.

Also according to your room diagram you will have some difficult reflections due to the hip roof. I think the bass boost you hear may be the result of your room and speaker placement. You might want to orient your position 90 degrees towards the large, tall wall and put your speakers along that<<=click here. Or perhaps even put your speakers under the hip roof and sit along the large, tall wall. Some expert advise from Real Traps, GIK or ATS would be in order here.