I’d agree the R9T variants are better looking than most, but it’s also double the price of some. There is a Guzzi Stone on the GS forum with v low miles for around £6k. How much is an R9.
It all comes down to use. The R9T’s may have a longer life in growth as a rider, if it’s about progressing - but it’s wholly possible most of the choices are going to be absolutely fine for day to day commuting and fun use.
Id also look at the Kawasaki Z900RS, which looks like a very nice option for old school looks, with modern electrics and a decent size tank.
For a bit of balance, I enjoyed taking the 125 to work today :)