yup ego 05 all the way!!
iv'e owned both and the ego 05 is so much better than the ion!!
yes it's more expensive but your want to trade out your ion after a tourny or so and an ego 05 would be an awsome marker to start playing with!
it's extremly reliable,
very easy to strip and clean and there is allot of after market help with them if you happen to get problems with it.