Don't believe what the agencies tell you. Their job is to get you to sign the initial contract, that's where the support will stop.And the promises.
Unless you get the upgrade to 330 in your contract (which you won't), the company will do what they want with you.
A few guys finishing their 2nd contracst were still not allowed to transition to the 330, or even swap their contract from 6/2 to 4/4.
It probably better to take one of the many direct CCQ 330 positions if you can. If your end goal is to fly the 330.
Good luck