Don't waste your money on Ronaldsway - fly into Andreas.
The primary runway itself (can't remember number/direction, sorry) isn't too bad, but the bit you need to exercise a little care on is the turnoff from the runway towards the parking area, there is a lot of loose gravel there, but at idle power taking it steady, you'd be very unlucky to sustain any stone/chip damage.
Just so you know, you don't have to fly into Ronaldsway for customs, you can fly straight into Andreas so long as you give the local constabulary a call beforehand letting them know.
Cheers.