Thanks IP, that defiantly is food for thought.
The only thing that still keeps me away from that path is that I'll need a JAA-PPL to fly a G registered A/C in the UK so in the end I'll still have to do the JAA checkride+exams. While I'm doing the ATPL GS (Which will be by distance so I can keep working) I do plan to fly now and then, if only to stay current, otherwise I'll be stuck in a situation where I'm taking a year out of flying to do the GS.
I think after taking what has been said into consideration, the easiest method is still to complete the JAA-PPL+NR, which I am already training for here in England, build a few hours to get some Xcountry hours on the JAA licence. Then in the year or so that it takes me to complete the ATPLs I can still fly here in England to stay current and take the time to get a FAA license issued, which takes up to 90 days. Once that's out of the way, build hours for the remaining CPL requirements in the US then complete the CPL here in England.