If I understand what you want to do, you can either restore the iPhone using iTunes, then re-jailbreak using redsn0w, OR use sn0wbreeze which will do the same thing in a single operation.
If you want to be able to restore your Cydia apps, tweaks, and settings, consider looking into the JB app "PkgBackup", which does what you would expect. It is a good way to restore your JB config to its former glory following a device restore...
Hope that helps.