The wider they are the more chance of a tree catching them and if you don't intend going wide on the tyres, changing the wheel offset or fitting wheel spacers then go for the 2 inch ones.
Tree damage!!
Fitting them to a 3 door is not hard, I did it on mine and I'm not panel beater!
You'll need to remove the plastic inner wing from the front and watch the fuel filler tube at the rear but other than that there isn't really anything to worry about.
Ask if you get fitting instructions and the seal between the arch & body included with the arches as some cheaper ones don't come with them!!
When I cut mine I used a jigsaw and clamped a piece of 1"x2" wood to the wing to stop it flapping around while it was cut. I would also use stainless self-tapping screws to secure them as mine came with normal mild steel screws which tend to rust!
You may have to do some sanding to get them to match the body correctly as well, mine were straight out of the mould but an electric sander did the trick. Also, if you need to drill the securing holes, be very careful not to crack the gel-coat.
Let us know if you need anything else to help fit them.
Here's my rear arch after the cut!
....and the front.
