How much are the coils? Should be able to get a pair of new coils to suit for around $200.
Remember though, you would want to get longer shocks too though for the full benefit.
Yes you can have them reset, no you are not allowed to cut coil springs - although I dare say if brown and cope (Dunedin) or Chamberlains (Chch) shortened them and then re-tempered them it would be ok... you'd need to ask them that...
Lol yes, I should probably stop trying to cut corners or springs for that matter. The last thing I need is an even stiffer rear end (it bounces around and steps out enough as it is already, happened at 90kays on bumpy off camber bend recently; new underwear required).