Got WA approval but VIC still pending. Should i wait for VIC or not

Hi Folks
I have been granted WA SS last week. I have also applied for VIC SS on March 5 and got an acknowledgement on 14 March.
Now I am confused that should I wait for VIC or go ahead with WA sponsorship and file 176. If I want wait for VIC, how long should I wait for. What is the most sensible cutoff date till which I can wait for VIC. I don’t want to mess up with WA SS as well by waiting too long for VIC (I don’t know I may get negative results also after waiting so long).
Further, is there any chance to change my state sponsorship after applying 176. Suppose, If I get VIC after applying 176 with WA, will it be possible to change it to VIC.
Your thoughts and suggestions are highly appreciated.

Thanks
SatymS