Do you have your SHSH blobs for 5.0.1 saved? If not, I would wait until an untethered jailbreak comes out for 5.1. If you can't wait, you can create a custom 5.1 firmware with redsn0w or sn0wbreeze to restore which will preserve your baseband. However, the jailbreak for 5.1 is currently tethered unless you have an old-bootrom 3Gs.