leopard geckos!! :D

well, i gave in :p petco had their 50% off with pals card, so i got two adult leopard geckos. they are a pair, the male is the albino and the female is normal colored. theres a pic of the setup too its not done, i still need something for them to hide under and a bowl of supplement. a few questions first though:

1.) which calcium supplement should i use to either dust or put out in a bowl? i have phosphorus free calcium with and without d3. and will they need a multivitamin?

2.) what does it mean when the male vibrates his tail? he has done it twice when the female gets on top of him, is this agitation or breeding behavior?