Consult a few suspension specialist shops and see what they recommend (Pedders, Dobinsons, etc). If you are talking about strut/coil spring spacers for your front, I'd be checking with authorities to determine whether they are legal or if installing them will change your suspension geometry or ride height to a point where police may consider them illegal/unsafe + check with your inurance company regards whther they will insure the vehicle with raised suspension (even if it is only third party-property insurance you will want to be secure knowing you are covered).