Should you deciede you want to buy a sub frame of course we can supply you with one. We also have steering modifications as well as an automotive rear wheel for the bike.
We do use Hiem joints specifcaly as they do have a bearing in them. The design of your mounts should provide all of the strenght needed not the conectors. With heim joints should you wish to change the toe in or lean out you never force stress into the system. This is also why we do not use "turn" buckle type struts as people will just cank on them to force the bike to lean in or out rather then ajdusting both ends.
Hiem joints also make it much easier to take the sidecar on and off.