Got an action army AEG 6.01 in my l96 and it's been brilliant.In my experience a mid price stainless barrel that doesn't look horrible inside will perform alright. Not to my standards of alright, but to your average airsofter. You see little serious improvement when then getting a Lambda, PDI, or any other barrel save for an EdGi. Where the biggest improvement is to be seen is in lapping, which is essentially what is done to EdGi barrels and why they are so good.
This can be done at home for quite little money and I have a guide, and can make a stock barrel perform better than most any you can buy.
As for the Crazy Jet, I'm fairly certain that ML makes the SSG10 barrel as it's priced like one of theirs, and he definitely uses a Maple Leaf in the SSX23 as it's got their name on it. It isn't a Crazy Jet, but there's never been substantial evidence on if it really does anything, so you could just get the longer inner from him.
Another barrel that is slept on is Action Army, they compare very similarly to a CJ, if not the same or a lil better, so I'd suggest one of them if you can get one. If you do get one, I'd recommend that you get a 6.01 as it'll get you a decent bit more power.