Did that a few years ago in a 172. Great fun, no problems at all and on a good day the view is spectacular. Call ATC before you go to get the opening times, R/W in use, etc. Lining up the approach can be interesting but no big deal.
It's quite a long water crossing - the shortest across water (about 14nm) is coasting out from Skye directly west to Wiay and then south across South Uist. Otherwise its about 35nm NW from Coll or Tiree. Make sure you have enough fuel - Jammy Dodgers at Oban
Runway surface is suprisingly good but I would suggest you hose the aircraft down when you get back to get rid of the salt spray.
Make sure you get some pictures!