It's been a while since I've messed with creatine but I thought it was concluded the loading phase wasn't necessary?
Never really read too much about GABA but I do like ZMA for the sleep benefits especially when training hard. Eric Cressey has mentioned how much he loves Z-12 which has GABA in it: ( It even gave me the Australian Biotest link)
I'm not usually one to take recommendations of supps lightly but if Eric Cressey thinks it's worthy, it might just be worth a shot. I don't know if it's worht 99 RRP, in the States it's $35 USD.