Any recommendations where to get 1.250 4 bar bushings? I have checked all the suspension manufacturers that I can think of seems most common size is 1.125.
Find a buddy with a lathe and make your own out of acetal rod or delrod. It will be easier in the long run.
Delrin is a bearing material. It has virtually no compliace capability. Your geometry may require the bush to flex to take stress our of the chassis and linkages.