Thanks for your advice Davyboy, it starting to make more sense the more I think about it, I do seem to remember a thread about trying to get a 2009 onwards engine but I cannot remember the reason why, but a change to the porting is the little bit I can remember. I will visit a few meeting to get a feel if max senior heavy is for me and it would be a good entry into the sport, I need to get my adrenaline fix now the Mrs won't let me race motorbikes anymore.
I will keep checking the other online site to see whats for sale as well as Ebay and figure the cost of an engine re-build into the price, a good retirement package or someone moving class would be ideal for me, will see what I end up with and keep you all posted.
It's a great shame that you cannot re-build the engines yourself, I have always built my own race engines when I did autograss as well as road racing and Enduro, but on the flip side be good to keep my hands clean for once