Good evening SteveJeal, by far the best job is a concrete base, but you do have to be carful with levels and size.
When i did mine i did a concrete footing then three courses of bricks, this gives a lovely finish and also helps if the surrounding ground is at different levels.
Inside i have a slabbed path bedded on mortar, gravel one side and a soil border on the other, but this is just what suits me.
The better you do the job now, the longer it will last.
