Mate i did a ctts course,
The problem with this is that Fibre is not being rolled out just yet, where as most of the world has it. All the cat 5/6 cable will get dug out its just a case of when, once we have fibre then the possibilites are endless for example South Korea has broadband speeds up to 1000mbs, which puts Virgin to shame.
Most of the lads ended up with BT, or Virgin. I my self did a few installation contracts, the money is good but jobs round the North West area are few and far between.
If you can back up fibre/cable quals with some I.T quals, and the usually health and Safety it would work more in your favour.
Here is the link to the one i did.
http://www.cable-training.co.uk/
Also dont bother doing the SDH course, no decent company will let a novice near one as a mistake can be costly.