The always elusive CAM question..

This is a little more rough than it needs to be. If you're running KB107s, and you're running factory heads of some sort, you will generally end up with a static comptression between 9 and 9.8:1. Unless you blueprint the block and heads and are careful about head gasket choice you won't reach 10:1. "Blueprinting" means taking care to machine the parts down to what the factory said they were supposed to be. Normally the block surfaces are "tall", and the head chambers are "large" compared to what published specs. If you have a valve job done and keep the valves, the chambers get even bigger. So - really it's not a big deal. The only question is do you need vacuum for power assist brakes? If you have power brakes, look at a cam around 225-230° @ .050. So of the three you posted - #1 (XE274H) is too large for power brakes but a decent 360 cam if you don't need vacuum for brakes. #2 (XE268H) is the largest one I'd use and the best "all around". I've used many of them and they run great. #3 will work but IMO you're leaving a little on the table in terms of performance.
With what you should end up with for static non of these cams should have too much cylinder pressure so they are all pump gas, which octane will depend on your tuning and the fuel you can buy locally.