Have you tried blackmountain thumb picks? If not you should give them a try. There is still a learning curve but I personally find them much better than anything else out there. I use the medium gauge (grey one) and also the black jazz version. I find the blue one is too thin for my liking.
Question: Do you necessarily need to wear a thumbpick for this style? No matter which size or shape I try I can't get the feel of it haha
Have you tried blackmountain thumb picks? If not you should give them a try. There is still a learning curve but I personally find them much better than anything else out there. I use the medium gauge (grey one) and also the black jazz version. I find the blue one is too thin for my liking.