Hey good luck with your challenge!
I'm currently grinding the STTs from $50 up to $1000, and I was using a 50BI strategy. I can imagine 100 is good if you're just starting out learning STTs. I don't see anything wrong with trying the 65BI.
I was beating the 1.20's at 17.5% ROI over a small sample, but was enough to jump to the 3.40's. The rake is terrible at these, but so are the players. Learn push/fold theory inside out, I use it when I'm below 10M (15bb), this really bumps quite a few % to your ROI.
Good luck with your challenge I'm rooting for you! Maybe I'll see you at my levels soon