Nature provided plenty alternatives to modulate the dominating effect's of Caffein. I think it has has when drinking Coffee as it seems to have the most side effects of all the forms I tried.
But I get your curiousity to RC analog's. I went through something alike and trialed all other Cafeinated plants I could get my hands on. And although nothing beats a warm cup of black ooze when it is in ones morning ritual.
The effect's of loads of strong Green Tea, which has additional Theobroma and Theophyline are of an whole other order then loads of Coffee. No jitters or heart attack mode. But a smooth tranquille stimulation that indeed seems appropriate for meditators. I contribute this to the L-Theanine and the slower release of the Caffein.
Guarana is smooth too. But different as Green Tea, manifest's among others in the cooling effect it seems to have. Tea seems more neutral/ warm cofffee is plain sweating when the temps are up. And it has legs. And like Green Tea, there ain't no crash. And no disruption of sleep either.
Kola Nut's are interesting as in you actualy have to be nuts to even begin eating one. But they do for century's in Africa. So I chewed my way through a few of them organ like things. Again strong Caffein effects without the negative downside's of Coffee. The shakes, the jitters and the crash.
Keep us updated if you get to try them, I am curious aswell Butyl