Data cable testing ?

I have looked everywhere on Google, Amazon, Ebay and Maplin for a cable tester. Will be used to test the speed of different firewire (800, 400) USB and Esata cables. Cables are used to tether high-end still cameras to computers, mostly for use in studios. A tester should be able to tell me which cables are toast and what is worth buying.
Should be an easy thing to find ?

How about this. 258991A PC Cable Tester Pro ATA. [Hobbes Tester] - Cpu Stuff

osxx said:

How about this. 258991A PC Cable Tester Pro ATA. [Hobbes Tester] - Cpu Stuff

Click to expand...

I had a look at that tester, but also need to know the speeds that cables can carry.