Hello and welcome!
You can change the pinion afaik to build your own 'quickrack'......which one was it again? You can also buy quickracks still which (if memory serves me right) are 2.5 turns lock to lock instead of 3.5.
I was demonstrating the chronic understeer/snap oversteer quite nicely in the 1500 yesterday, need to do something about that! Better rubber, 210lb fronts and 180lb rears may be arranged soon, along with 2" off the ride height.....might just use standard new dampers for the meantime or a set of, as mentioned, AVOs from Jigsaw or someplace.
Certainly you need some uprated springs but for rallying I am not sure what would be the best configuration.
I rang up to get mine sorted from South yorkshire springs. Ace company who actually manufacture rather than buy in. Quoted me under £120 for the 1500, any Rate, any length, 4 Coils including VAT and delivery. Would take about ten days to have them made.
He had good suggestions on what to use so may be worth ringing up and asking him?
Its where MC Rallying used to buy from before they went all Maxy pants bodykits
Phone number is : 01709 375375
Also worth getting in touch with
http://www.coilsprings.co.uk/ - they prefer the classic stuff