10.5-11 is Euro 45 anyway. That should be just about right if you prefer thick socks. Always best to buy shoes in person though if possible.

I only mentioned the size thing because it's a bit different than sizing a say a hiking shoe. Fudging a size upwards just to be sure they don't rub is a mistake. You want them right sized. If there's room for fore and aft movement it can get pretty uncomfortable.

I'm not sure why, but the shoe size conversion charts I find on the web are wrong more often than not, and some of them are way off.