Tire choice for Trek Pilot 5.2

Traded for a 58 cm Pilot 5.2 this weekend. Not sure what year (05, 06 or 07). Came with 700 x 23 Ultra Gatorskins. Tires looked nearly new but do have some age on them. A google search suggest they dropped the Ultra designation in 2010. Anyway, I have a bike with 700 x 32s but it’s a disk so without pulling tires off to see, was wondering if a 32 would fit. I read somewhere that 25 to 28 was about as wide as I could go due to the brakes not letting out enough. I know I could air down the tire. Anyways, what’s the most comfortable tire I could put on the Pilot. Was leaning towards something like a marathon supreme but it don’t come smaller than a 32. Want a durable tire that don’t sacrifice much speed but I’m 57 and won’t be racing. Just riding for fitness and fun.