Roadstone are nationwide and they have a large selection of gravel. However, in the end I went with Finbarr O'Neill in Ballincollig (Cork) for their "Pink Granite", nine month ago.
It looks really well when it's wet and as it's ageing the dry look is improving.
We used a separate driveway contractor to do the work and to add kerbing. I did the kerbing design myself.
Make sure you get a tonne extra of gravel and have somewhere to store it. This will come in handy over the years for repairs (which you can expect to be minor and easily done).
The advantage of gravel are many, including:
Low maintenance, and that which is needed tends to be minor.
Clean, any dirt gets washed through it by the rain.
Burglar deterrent; apparently burglars do not like it because of the noise when walking or driving on it.
Drainage: no additional drains required and puddles never form.
Finish: because of the rough finish average undulations are not visibly obvious.
Sorry, I don't have the costs.