What sort of height are you looking for? Do you want winter colour or something that will look good all year? My answer to everything right now is heuchera so I may not be the best person to ask but the colours you get are fantastic, they like the shade and can get flowers - would look great lining a woodland path.
On a quick google search found Pachysandra terminalis (second plant listed) gardeners world link which grows to 25cm high by 60cm which might be a nice alternative to box if you want something less formal
I love alchemilla mollis but DP is not so keen - I can get away with weaving it through borders but I don't think he'd let me do a full pathway with it
I think I want something a bit taller than pachysandra weed although I do like it.
I suppose it doesn't have to be evergreen, but something that looks nice for a long period of time would be nice. I'm planting up two deep borders either side of the front door, with a path through the middle, so I want something that will line the middle path if that makes sense?
Perhaps I could do something like a low privet border with the alchemilla plus bulbs in front. That might look nice?
I love Ajuja. Is spreads by runners, so it will cover your area really quickly. It is one of the easiest plants to control. Just dig up any bits of it and plant it somewhere else. Despite its spread it is a very neat plant. It starts off with glossy black leaves then ensign blue flowers. Just make sure you pick the one you like as there is a huge variety. I don't like the insipid ones or those with variegated leaves.
I would plant behind it a low growing stripy grass in green, white and yellow to really make it zing. Or, if you don't like grasses white thyme interplanted works well.
My alchemilla mollis isn't evergreen but it lasts a very long time!
I'm now wondering whether to do a nice grass like a stipa with spring bulbs planted along too. I don't mind compromising on not having evergreen, as long as it's not something that looks nice for a month!
My plants to go to for pathways are heucheras, aubretia, thymes, alchemilla, sweet woodruff [esp when you want ground cover under trees etc], with things like garlic chives, echinaceas, short grasses running through them. I have one new bed completely surrounded by chives.
Growing disease on box does worry me, especially after Monty got rid of all his box balls!
Riding I don't think choisya is quite right for the path, but I've made a note of it for elsewhere in the border as it is lovely!
Alternative your garden sounds lovely. I've got aubretia, thyme, chives and echinacea in the back garden and I do love them, so maybe I will divide some and plant them in the front. Sweet woodruff also looks great - I think I may plant some of that in the front of the borders.