I would have though pretty much any garden centre or your nearest Wilco would have a good range of styles.
I bought a solar powered ‘string’ of lights, which are contained in a clear flexible tube, and are pretty bright.
I got them to highlight my tent last weekend, and ended up wrapping them around one of the guy-ropes, because people kept tripping over it despite them being dayglo orange with reflective threads; people don’t seem to understand the concept of using a torch after dark to see where you’re going!
It worked very well, so it might be worth considering using those, each ‘rope’ or ‘string’ is 5m long, and could be clipped along a path, for example.