Shouldn't have any problem with what you have.
I toured with 700 x 25mm Schwalbe Marathon Kevlar this year on my cyclocross. Excellent tyres - no puncture problems, and they roll very well too so you're not going to be slowed down too much in comparison to slicks.
I was carrying a fair bit of weight too - 2 large rear panniers, a rack bag, plus tent and sleeping bag strapped above the panniers