don't have the car here with me to check but i'd say they are between 5~7mm internal diameter. i doubt if they are larger. if unsure, always get rubber hoses that are a tad smaller coz they can stretch over the connector nipples to give a nice fit..
Pull 1 of the hoses off the metal pipes that run above the top timing belt cover and measure the pipe diameter to be sure. For the boost gauge I would go for 4mm if you are going to tap if off the FPR or map senor vacuum lines. Dont forget about a T piece for that one.