Cheers for that.
have to say that wendy at reprapmall.com has been extremely helpful. Both in answering questions quickly and accurately and in supplying me with the .stl file for the single extruder carriage.
From what i can work out - reprapmall are the actual manufacturers of the kits. So she didn't mind that I bought it from someone else, lol
So one thing you do get with this kit is excellent support and customer service - can't fault that in any way. :-)
Very helpful and very fast response times to any questions.

Right I'm off to see just how fast Alexa can print pet-g and work out what the maximum speed for pla actually is !