Have you got the option of a birth pool? Because that will do exactly what you're after - take the pressure off your legs and provide some pain relief.

I found hot packs and my doula applying pressure to my lower back were also good, as well as the fit ball. I used the fit ball leaning over a pile of pillows on the bed or chair in front of me (no boob pain then!).

Honestly, how you cope is going to be in a large part reliant on your mental state and how well you prepare, not just the available drugs. A doula and a calm birth course might be just what you need. Did you try those the first time around?