oxygen concentractor equipment needed

I have been suffering from cluster headaches now since 2014,I have at least 6 attacks a day,3 at night time.I have 2 concentrator machines down stairs that I had loaned from the NHS.they do there job well.I also have 4 big oxygen cylinders down stairs,the NHS will only supply 2 of these machine's because of the cost,but I need another two for up stairs because they are very heavy to lift and they are fixed downstairs, 2 more upstairs would make a massive difference to my condition which is permanent.I also have 4 portable cylinders for going out but they are heavy,so I need a invacare solo2 portable oxygen concentrator because they are much lighter to carry and half the size of a regular tank.and Schrader valves,each machine costs £1,800 each thanks.