hey
50-110? I am assuming thats the full adult range and not the springs lol. If you can get adults get adults. Will be much better. If you are getting powerisers then it is probs best to go for 50-70s.
Sprog is the expert on brands and what is better but I will try to help lol..
For starters...are they poweriZers or PoweriSers. There is a difference. I am gonna assume they are PoweriSers because you have mentioned the pro's. From what I have heard at the mo Projumps are the better choice. I have PJs. Love them. I just havnt tried poweriser pros to compare. I am not sure if PJs are any better but I think the frames are more durable and the springs a bit softer which is probably a good thing for you. Also, the support is really really good and they cost less.
but...they dont have the size you would need atm. You would have to call up and get some springs changed over. Would cost an extra £15 for the same thing. If you dont want to wait great option if you choose projumps. The springs you would need would be M60.
But actually, before I say adults, how tall are you, if you are less than 5ft you will be a bit short for them.