Your choices really are limited to EECO and ITI, however you are much better off taking the jacks out, have them resurfaced at a hydraulic cylinder shop and reinstall. Schindler's sling is just 10 ga. galvanized, so you need to build and entire second sling to lift from, as the new jacks will have a pickup point above the cab, where the Schindler sling has a pickup point at the bottom of the car. This in turn now will most likely require more HP, which requires a new motor starter and most likely disconnect and feeders. Oillift stopped selling the GMV jacks, which we have used in the past for jobs like this, they had the smallest heads, so were the better option.