A 26 mile round trip is a fair bit, but not too bad (mines about the same). You might find just doing one way at first helps, or alternatively just cycle for some of the week. You're bike should be fine, but again I recommend getting a good pair of tough but fast rolling tyres - I like Vredestein Spiders, which are available in 700c and 26" - if you're running 26" Specialized Armadillos, or Vredestein S-licks are also worth a look. A rack and a pack or pannier will be useful.

Richard