Should I buy Pool Party Lulu+Lulu or Program Lissandra+Lissandra

I'm gonna get 3700 RP and I have enough to buy two 1350 skins and a 975/880 champion (And have enough RP to do nothing after. Basically I'm asking if I should wait to buy Lissandra with IP or Lulu with IP (Currently at 2.2k IP) Either way I'm getting all 4 things listed just gonna be delaying 2.