Supposed to get my new bike next week. I will be putting these GP 4000s tires (120 psi Max) on it and wondered what tire pressure I should go for on the rear and front tire.

I'm 6' 2 3/4'' and 205 lbs. The bike is supposed to weigh about 20-21 lbs.

Also, is there a good pressure gauge out there for presta valves other than those already attached to a pump?

Thank you!