The problem may not be the irons, it may be the ball. Do you usually play with the free starter one? If so, that's why you're getting no spin. Irons that give a lot of spin only work with a ball that will also spin well. Have a go with something like the L33 Callaway ball and see how you get on.
If you really want new irons I'd wait a while and go for something like the Speedblades at L75, not very far away really.
In all honesty though I think the irons you have will see you through to the L85 Nike irons.
The higher level Clevelands have a lot more spin, at times a bit too much which is why I use the ATV wedges. They're right between what you have now and the top Clevelands for spin.
Good luck with whatever you decide.