It's not ride height you need, just stiffer springs. Is it rear or front that bottoms out?
The standard springs are designed for the average person, let's say 85 kg kitted out. So, if you increase the spring rate you'll be fine. Just ask a specialised shop for a rear spring that is suitable for your weight.
If it's the front that bottoms out, you can change for better aftermarket springs, there are no personalised springs available as far as I know. Might be your springs are a bit old and thus lost some rate.