I'm a 7.5 in street shoes, too, but usually wear an 8 in athletic shoes (sneakers).

I have doms in 40.5 and 41. The latter are a smidge roomy but are good for wearing with thicker wool socks if it's chilly outside.

Even with wider, 'pre-bunion' 46 year old feet, the 40.5 fit and feel great.