Rear springs advice pls

ive just put a set of 17" bk racing alloys on my mk1 1.8 gti cabby and the tyres are slightly catching the outside walls on the plastic bodykit arch, ive had a look and the rear springs are shot as they are pretty much closed up so i think with new springs it should have plenty of space, it did when i jacked the car up put the wheels on and then took the jack out as this released the springs to full stretch as then should be but of course when i started to drive away they collapsed again,

my question is what are the best springs to get for the rear, is there an alternative diesel or van spring i can use that fit and are stiffer, would caravan rubbers be a better option to stiffen the new standard springs up, what have other members done on here, im hoping to not have to roll the arches if possible

This is a mk1 technical question on running gear not general chat so moved to running gear.

My springs were sagging on my 40k tin top. I opted to go original as there are a lot of variations of the same spring to cater for all the different models. Jetta, Scirocco, cabby, tin top, GTI, van etc etc.
VW colour code them with a blobs of paint to identify them.

Whatever springs you use your wheels will still catch because of the clash point you have created - just not so often if they are stiffer.