Thanks for all of your responses, they have given me a lot to think about. Apologies for not getting back to this thread sooner, have been flat out with course work, and helping my sister and her DP move house the past couple evenings.
To answer a few questions - DP is very supportive. The way he sees it, he has been following his dream, career wise, for the past 10 years (he is a few years older than me, and in the music industry). He figures that it is now my turn. Also, when he started down his career path, I was working full time, so financially supported him (as well as setting him up with his first big break), so he now wants to reciprocate. Now, I am not looking for reciprocity, or 'payback', but I really do want a shot at my dream job.
TBH, he is away with work a lot anyway - we might get 10 mins one night, a quick dinner another, and then he is away for a few days. It is bloody difficult, but we make it work. We love each other dearly and trust each other explicitly, which I guess helps.
Re: TTC. Yup, lots of years, 4 MC's, and my last pregnancy was Jan 2010. Really, really think we need a break. It is starting to consume us and take over our relationship. Plus, as we started TTC so young, maybe we need some time to be career-focused and selfish. Which is where this benefits DP - he loves his work, and only comes home for 10pm most nights because he is coming home to me. If I were away, he could throw himself into his work for as long as he wants, as could I, and then our weekends would be just about us.
Finally, the full-on, away from home work is just for a year, but the job would continue to put considerable demands on my time. I would, of course, be entitled to Mat Leave, we could still have a family. Well, assuming we can anyway - we have the same GP, who reckons neither of us have any need for further investigations. Perhaps time away from the suffocation that is TTC would help us.
Sorry for the epic post. Have been thinking about this all day, and have poured all of my thoughts out here - can't really talk to anyone IRL about this. Thanks so much for all of the advice and wise words. Much appreciated. Sorry if I missed any questions / posts. My brain is well and truly fried!!