I'd say cook it at 325-350deg...aiming for a internal of 120-140 depending on how rare you want it. Should take 1 1/2 to 2 hours with a bone it. Now for rubs........here's what I have used before:
Ginger powder - 2 tsp
Cracked peppercorns - 2 tsp
Mild chilli powder - 1/2 tsp
Mustard powder - 2 tsp
Turmeric - 1 tsp
White wine vinegar - 3 tbsp
Salt - 3/4 tsp
.......Good Q'ing