Best A2 Choice Moterbike?

I'm looking to get my A2 restricted motorcycle soon and I was hoping someone with a bit more knowledge than myself could give me an insight into my options. Primarily I'm looking at the Honda CBR 500 R, CB 500 X, Harley Davidson 883 (restricted) and a few others. I'm roughly 13 stone and 6ft, and feel myself cramped on the older CBR 125. My main concern is comfort as i ride regularly, as with my cbr 125 my back begins to ache after 20 minutes or so. I've ridden a Kawasaki Eliminator and didn't feel at home with the slow cornering and love the agile movement of the honda, would the 883 have a similar slow cornering?

Any insights or opinions would be appreciated,
Cheers.

"My main concern is comfort as i ride regularly, as with my cbr 125 my back begins to ache after 20 minutes or so…"
The CBR-500R has a similar riding position, so that rules that out.

"I've ridden a Kawasaki Eliminator and didn't feel at home with the slow cornering… Would the 883 have a similar slow cornering?"
Yes, but with inferior brakes and suspension, into the bargain. Strike out the Harley.

Two down, which leaves one.

If you check link below and then select Category A2 it will give you a list of A2 Legal bikes and if they have to be restricted or not. If you have a Preference you can reduce the list by selecting Make

Andy C

Have you looked at something like a Suzuki Bandit 600 (Restricted). They're pretty much good all-round bikes, cheap and reliable, near vertical seating position to so basically sit up and beg. You have the best of both worlds, decent performance with a nice seating position.