Thought I'd update this in case anyone is looking as well. I emailed a handful of authorized Koni rebuilders, only one of them got back to me (Performance Shock). According to them, they're only available out of Koni in Holland and there are none in the US. I didn't get a quote but they estimated about $40-50 for the one bushing with a 12 week lead time.

My reasoning for getting one was because my two rear shocks are both LHs so the compression adjuster on one side faces forwards which makes it a PITA to adjust. Still doable though so I'm just gonna leave it