Hello there,
For 8 CCTV system... I would say to buy vandalproof cameras, a minimum of 600TVL and IR on all of them will be great.
You can find some great prices on [mod edit: store link removed]
An 8 ch DVR with 1TB is less then £200 and good cameras around £70-£80.
I would recommend cameras with 2.8-11mm Lens, so you can adjust them.
On the whose installation you can use video baluns, in that case you can run 1 cat 5 up to 100m. There are around £10/ pair.