Cheers guys for a lot of useful and thought provoking comments.
I've decided to park getting the twin rating until I'm the other side of gaining a CPL.
Whilst yes, it could be obtained now, I've come to the conclusion that I will prefer to target getting the CPL under my belt rather than the further endorsement.
Whilst I feel I'm getting there, I know I'll still have a reasonable amount of work on getting up to CPL standard and would like to have the necessary fundamentals well sorted before adding the extra complexity of a twin. I could push myself and try for the twin rating now, but I just feel that I'd prefer not having that extra workload to think about whilst I get to grips with the extra components for CPL - something I really want to master.
The comments made above would seem to endorse that a twin rating before CPL is not for everyone, but can be for some people. Its therefore an individual choice, and my choice will be to park it for now.
Thanks again guys - I appreciate all the comments.