I was in the same boat as you m8...i bought a s-16 and asked advice , most peple told me to get a tank, but in the end i decided i wanted to be totally self reliant. So i bought a rws pump from jsr for 97 quid, and to be honest it isnt easy to pump to 200 bar, but i find it ok(although i am young and fit). Bear in mind that you have to get a cylinder tested every five years and 300 bar is the only option in my opinion. good luck whatever you decide
cheers
jonathan