I just use regular spurs whenever I am in the hunter ring, jumper ring, dressage ring or eventing. I have never had any issue with them and I have shown gold shows for hunters(compareable to A shows in the US)
I would get whatever you're the most comfortable with then.
Personally I think a bigger spur is easier to use because you can make your aid more subtle but if your leg has the possibility to spur your horse by accident then I'd get something smaller.