Available from all electrical wholesalers, possibly also DIY Wharehouses, cpc.co.uk. etc.
If you are running cables up straight conduit in a mast stiff fencing wire may do if you have access to some. If there is no conduit you may need rods, again electrical wholesalers usually do a pack of 10 rods which screw together. I have also used a hand crossbow with fishing reel mounted on back. Bolt pulls cable off reel until hits cardboard target, fishing line pulls through draw cord enabling cable to be pulled through/across. Airline security v. intested in that one pre 9/11 when I was working abroad.
I used one made with a tiny chain on the end, like the one going into the hub on Sturmey Archer bike gears, which didn't get stuck easily but provided a gravity grip.