I've been itching to try Class A too with a similar budget...
After researching I came the conclusion that full on Class A was a bit too pricey and concerns about the heat they pump out too so I went slightly left field. First looking at Class G where I found...
1. Arcam Class G. Older models A29 (~£350 used) A39 (~$500 used) / Newer model SA20 (£1,000) - They all output the first 20w as Class A. None of the heat/size issues. Reviews generally positive "warm smooth sound". Though one or two reviews found them "a bit dull".
2. Creek Audio 100a (~£1,000) Similar Class G to Arcam, outputting 25w as Class A. Has all the positives of warm/smooth Arcam sound but reviews state "more clarity, details and dynamic" vs the Arcams. Not seen a single bad review on it (note: the 50a is NOT class G, it's class A/B) Almost pulled the trigger on this (there's a second hand one on Ebay and the owner was ready to accept £975 for it). In the end though...
3. Schiit Aegir (£800 I found a used one on ebay for £550 which I just snapped up and I'm waiting on) Touted as "continuity class A" which I've no idea what that means but it basically seems to work more or less like class A but without the heat/size issues. Outputs 20w into 8ohms / 40w into 4ohm but can drive speakers like LS50 ok apparently (measured 83db sensitivity). My speakers are 89db so should be no problems there. And should you end up needing more power then can go monoblocks. Not seen a single bad review and everything points to having that class A sound. The
Stereophile and
Stereotimes reviews sold me.
One day I'd like to try a fully fledged bastard of a class A based system for now the Aegir hopefully gives me a very good taste without my room becoming a sauna or skinting myself out.