Long distance just need a vest and shorts and a pair of spikes
or trainers for racing.
In addition to this some warm clothing such as sweatshirt and
tracksuits trouser are needed for warming up. Trainers should also be worn
during warm ups and warm downs.
Your trainers will generally need to be better than a sprinter would need
as you will be using them for a lot more mileage. Although, generally, you
get what you pay for, it is certainly not necessary to spend a fortune on them.
Pick a pair which are comfortable and have good cushioning and supports. If
you are prone to injury - getting advice on trainers may be useful as some
are designed for those who either over or under pronate.