Practical Raising

Hi I have a rover metro which I will be taking on a long drive down to Morocco in the summer. It all seems mechanically sound but seems to sit quite low to the ground which worries me considering the sorts of roads down in northern africa. I was wondering is there an easy way to raise the suspension height a few cm to get that extra bit of clearance, hopefully without having to replace the actual shocks or anything major or expensive. Also does anyone know what the largest wheels the metro can take are? Lastly will this be any different for my friends cinquecento which will be taking the same trip? Thanks alot for any help anyone can give, If you have any more advice on readying the metro it would be great too.