Johnny, here in the UK there is company that has been around since turbines were brought out for model jets, (Microjet Engineering) they have just developed 2 new engines, the
Phoenix super panther which is smaller than a KJ66 and alittle larger than a MW54 (ram500) and gives 20-22lbs thrust, weighs 2lbs and the Phoenix MK5 which is 1mm larger on the outside to a KJ66 and produces 32lbs thrust, these might be worth looking at as they are quite cheap for the quality of build, checkout the website http://www.microjeteng.com for more details or email me

apart from that AMT are great but a little heavy and expensive and RAMS........thought they'd shut down

Paul j