I'd say XL definitely, in the current jets
The determining factor is your boots, not your shoe size
I wear 9.5 shoes (42 Euro I think) but have L jets
I use 3mm booties with a thin rubber sole on the bottom
I've tried booties with a moulded sole, and there's no way they fit into my fins - too wide
SP changed the size of the foot pocket a while back, with the current fins having a much smaller pocket
So if you get 'old stock' jets, maybe L would be the right size for you then
As someone observed, the paddle size is significantly different between the sizes; that's an odd design choice IMO - I'm 6' 80kg, but have a smaller paddle than friends similar sizes, because they wear booties with moulded soles :confused
I'd second the spring straps recommendation. I bought Halcyon ones, but if I was doing it again might get XS Scuba ones instead - peening over the pins was a PITA