I'd personally do an upper lower,focusing a lot on bodybuilding and gpp
After a while I'd either do 531 or westside
The way I'd focus on gpp is:
1.On upper body days for warm up I'd pick a tricep , a back and a rear delt movement and start from 2 cycles of 20 reps each slowly trying to work up to doing 3-4 cycles of 20-25 reps without it affecting my workout.Take a look at my log to see how I do it
2.I'd try to add supersets after a while,shorten the rest periods ect.
No need to hurry in any of the 2.Your priority should be to get in some solid work