Roundover bits are some of the most common bits and are normally what is used for rounding edges as long as you leave a flat in the center of the edge for the bearing to register against. Even when rounding the full edge round I'll still somethimes use a roundover bit instead of a bull nose bit which rounds both edges at the same time. When rounding the full edge over you need to either do it on a table with a fence or clamp a straight edge to the board or use a guide attached to the router. The bit(s) to round a 5/8" thick board are relatively small so you shouldn't have any problem running them but the key is to always listen to the router and if it is running too slow then slow your feed rate down. That's true no matter what size router you are using. Welcome to the forum by the way.