Yes you can use stock blaster shocks but, your bike is going to be about 2.5-3" lower in the front than stock.
As far as the a arms go, your not going to get more travel out of the diamond j kit. your bike is just going to be wider. The only thing that the diamond j kid does is move the shock mounts and a arm mounts out a few inches.
if you want more travel then your going to have to get different a arms and long travel shocks.