Thanks for the advice Ken, it does seem a very tricky choice, i am looking at about 4 cameras, still not 100% sure, i liked the spec on the E500 and i thought the twin lens kit would be enough for me for a while..still looking though, probably won't buy till january anyway, sales etc..
Although i do mostly rock art, i also do standing stones, circles etc...but i am thinking about doing more nature shots..so again that is something else to take into account.