Of the brands you mention, I would go with Sugoi. I'm not familiar with their warmers, but I like their jerseys and shorts--good quality stuff.

As for sizing--"generally" match the arm warmers to the size of the jersey and the leg/knee warmers to the size of the shorts.

Of course with cyclists you have to use some common sense. If someone wears a Large jersey because he has broad shoulders, but the elastic is loose around the biceps, you will need to "size down" on the warmers. Same thing with the shorts/leg warmers sizing.

Good luck. Hope he likes 'em.