I have a PPL and have considered getting my CFI-SP as well. The local FBO has a J-3 and they offer SP training as well as tailwheel endorsements, etc., but their only CFI with a tailwheel endorsement has limited availability... my friend who was pursuing a SP certificate gave up and decided to go for his PPL in a 152. Not that I'd be much different if I worked for them, I have a day job, wouldn't want to commit to the time to train a beginner student but wouldn't mind getting paid for the occasional tailwheel checkout or BFR. One issue with this is that if you don't pass a certain number of new SP students per year, you have to repeat the checkride on a regular basis, more hassle.

I had also thought of offering ultralilght instruction in a 2 seat Quicksilver now that they've said they will issue LODAs for primary instruction in ELSAs... but the requirements to get the LODA (detailed lesson plans, etc.) are fairly onerous. Now that the BFI program is dead, it would be great if one of the organizations that formerly had a BFI program, EAA, USUA, etc., offered a lesson plan program for SP CFIs so that they wouldn't have to create it from scratch. Unfortunately, EAA seems to have abandoned ultralights (and almost abandoned GA), and USUA does nothing but sell insurance policies.