Hey Joe,
Off course your allowed to mention your t-rex, we just dont allow links to other retailers and obvious advertising
With Powerskip springs you need to go for the extreme use for your actual weight rather than one for the standard user... below is the chart
PS640 Recommended bodyweight Maximum jumping height
standard use: 95-115 kg 1,40 m - 1,10 m
Extreme use: 70 - 95 kg 1,90 m - 1,40 m
PS580 Recommended bodyweight Maximum jumping height
Standard use: 85-105 kg 1,40 m - 1,10 m
Extreme use: 60 - 85 kg 2,00 m - 1,40 m
PS520 Recommended bodyweight Maximum jumping height
Standard use: 75-95 kg 1,40 m - 1,10 m
Extreme use: 50 - 75 kg 2,00 m - 1,40 m
I think the only two people on the forums that can tell you if its better just to go for just the frame or the whole powerskip would be Colin or Kiola.