I would avoid ATC SCM7 (or 11/19) on bookshelf or wall brackets, really not designed to work so close to the rear walls, same with my SCM10s, they really do like a little space, not multiple feet but still. The HTS7/11 would be a far better choice.Second hand baby ATC, either the 7 or the 11, (the 19 will likely be over budget), but sealed box design will work well as near field listening monitors.
Or as mentioned the LS3/5a, but these can get expensive.
Or the old Cura speakers are a good option.
Ha i have a pair of D2's and a sub in my main system downstairs.I always end up back with a pair of ProAc bookshelves and a REL sub in my study, going back to the 90’s. Tried all sorts, something about the ProAc sound sig suits my ears, like to try other makes every now and then just to see what’s out there. At work I have some Dali that are very nice and not expensive, with OP budget though I’d look for some nice Tablettes as Alun says.