Unable to restore applications after hard drive replacement
When you say "cant get anything to restore", do you mean 


you're having difficulty getting your data back onto your new drive?
You are having problems reinstalling software (either from the original install media or DMGs) you had before the drive swap?
Software from a TimeMachine backup is not running after you try and manually restore it back?


Now that you have Snow Leopard installed, is this the same version of OS X you ran previously? If you did run 10.6, what update version did you run? 10.6.8? 10.6.7? Or, since you had paid for Lion "ages ago", was your iMac running 10.7?

Your best bet is upgrading to and/or installing the version of OS X your iMac ran prior to the drive replacement. If this was Lion, you'll need to update to 10.6.8 first, then you can redownload Lion. 

Once you have your OS back to parity, you should have an easier time reinstalling your software.

One other point to consider: if you are downloading current install files for the software you ran, you might not be finding the same version you ran. Newer versions of some programs may require Lion or later to run.

Good luck!