That build diary is a couple of robots out of date now, but I'm still using the same powerpack. I did start with a bladder inside the silver tank, but the prolem is you can inspect it to check it is OK. I moved on to a seperate and much thicker bladder without the silver tank.
You could probably use the powerpack for your lifter, but you are limited on flow rate on a pump that small, so it would all depend on the size of your ram and the linkage as you say.