Regarding Related Moves-
http://www.smogon.com/dp/moves/avalanche
It lists payback as a dark type equivalent, however Payback has 0 priority as opposed to Avalanche's negative priority.
Revenge, however, is the fighting type equivalent to Avalanche.
http://www.smogon.com/dp/moves/icicle_spear
Arm Thrust is said to have more power and less accuracy; in fact it has more power but same accuracy according to the
arm thrust page.
I'll post more if I find more.