Hi Buzzy! Welcome back to photography and to our corner of the universe! There are many FF offerings from Canon - it depends on how much you want to spend and what kind of photography you do. Maybe one of the UK denizens (@Lester Wareham, @Terrycanon, @garryknight, etc.) may chime in, since I don't have a good feel for prices across the pond. I think that an R6 Mark II would be an excellent choice for general purpose photography. An R5 Mark II would be considerably more capable (and also considerably more expensive). The Mark I version of either the R6 or the R5 are also excellent and may be considerably cheaper although consensus is that the Mark IIs are better. The R1 is the king of the hill but also commands a king's ransom.
Seriously, I wouldn't think you can go wrong with an R6 II. I don't have one, but I see excellent results from people who do own them. I have an R5, in fact I recently bought a second R5 body, having decided that spending the extra for a R5 Mark II wasn't worth it for my kind of photography. So I believe an R5 rather than an R5 Mark II would be a good investment. Looking at the Wex website, I see the R6 Mark II costs £2,199, while the R5 Mark I is £3,149. The R5 Mark II costs £4,499. I didn't consider the extra was worth it for me, tbh. I bought a second R5 instead, and planned to sell my original one. Now I'm keeping it to save me switching lenses all the time. I just couldn't let it go!
