Best speaker combination for an Sugden A 21 SE

I've a Sugden A 21 SE amplifier and make a lot of experiments at the moment. Any tips for the best speaker combination in a room with about 30m²???

I called Sugden.
Tony recommends the high end B&W line and also uses full range, Pro Ac Response D38 in their demonstrations.

I use the B&W 805-Signature with my Sugden. Nice.
castle severin or harlech
I use another british legend - spendor s6's (not the newer s6e) which appear to be a match made in heaven. I tried living voice, sonus faber and a few others plus others in the spendor range. The s6's were a beautiful match with a coherence that is hard to beat. They are open, dynamic, clean, organic. Beautiful.