What cat5e to buy

[PAULJ5555]

Hi

I need 100m of cat5e cable to wire in some rooms at home for internet/smart tvs, what shall I buy?

Thanks
Paul

[PAULJ5555]

Solid core copper on ebay 12.99 for 100m, whats the deal with buying this as apposed to the £40 stuff.

Also should I use the shortest lengths I need when installing. Do you loose signal strength the longer the cable.