If you have a 2year contract, and don't really wan't to move, stay. As you said there is the possibility of a second contract at the end of it, after which you should be offered a CID (contract of indefinate duration). At the end of 2years , and another contract is not offered, maybe then look to England.
If you choose to work in England, stay away from inner city London schools, pay is higher, but a nightmare to work in, and a high turnaround of teachers. Pay in England, starts low, but you can move up the payscale very quickly. A work colleague, who joined us last year after 6 years in England, claims he is on the same salary as he was in th UK.