It seems clear they want a ditch ( sod and stone , IMO your bank will pass) and a grassy margin beside the road , unless you intend to mow the margin ( and you know the issues with cattle and lorries wrecking it ) get grass seed at an Agri CoOp . As you have effectively moved back the old ditch , you can plant ( to the back of ) the top ridge.
Remember that even if you make a total mess , it will be very much in keeping with the country side .
If you are into it , a wild flower mix beside the road ( at Lidl last week) and some sceachs with simple rampling/climing roses , wild hunnysuckle would look great .
pjq