Dont worry about it warming up quickly, thats normal, my 4x4 is the same and has been since i bought it 4 years ago. Ford water temperature gauges are renowned for being crap , as long as the needle sits somewhere within the NORM range and doesn't overheat and as long as the twin fans cut in when they should everything will be as it should be. As for a secondhand chip, well you could bid for one on ebay but thats a bit dodgy, alternatively , post a wanted ad on here or the RSOC site , there's a lot of new cossie owners upgrading their cars to stage 3 and most would be happy to sell you their old stage 1 chips.