Front brake advice

Had the old bus MOT'd today and as expected, failed on front brakes so my garage changed the pads. They said one caliper had stuck pistons but they managed to free em off and get things working but they said the caliper was worn and that I should be wary in future of any sign that the car's not braking in a straight line.
Any thoughts on whether I should renew the caliper as a precaution (heading back to Spain in a few weeks where parts and garages are expensive!) or would a repair kit normally be enough? I never worked on brakes and don't really have the time or the tools with me to start learning right now...not even got me manual!
Do calipers wear out and would it be wise to do both sides or just the dodgy one?
As ever, thanks for any kind words of advice :cool2:

Disco calipers are known for wearing and a re-furb kit won't fix that.
If I were you, I'd replace both front calipers before heading to Spain - they aint that expensive and brakes aint worth compromising with.

wot he sed ^^^^
dont short change brakes - its your life yu are playing with.

thanx for comments. Spoke to garage again today, said only 1 piston was a bit sticky and although they said they'd be glad to take my dosh, they don't tthink I need to change em, so I'll see how it goes for now. Still got over 2 weeks before long drive.