Hooley, go with what you have previously used if you already have equipment or experience (live exper, or simulator).

If you have not yet flown on either, I will make the suggestion using of Mode 2. This is based on the fact that most hobby shops and distributors stock radios configured for Mode 2, as well as the fact that there are almost no Mode 1 teachers around anymore. It is not difficult to convert radios that they have in stock in most cases, but it is easier to start out with a radio configured the way you want it.

PS. I learned on mode 1, can instruct on it and flew it for 15 years or more, but several years ago I taught myself mode 2. There are genuine benefits to each that you may find later...... (these are only my opinion, but it is based on experience with both modes)
Mode1-- easier to fly handlaunch gliders on, pylon racing is more intuitive on this mode
Mode2-- some aerobatics (including 3d) seem easier on this mode