Thank you muchly! Can I use a Kayfun on an LP?
Yes you can as the Reo has a 510 connection but, by doing so you just can't squonk which in turn defeats the purpose of the Reo. A Kayfun can however be useful to change flavors for a while with out having to empty out the juice that is loaded into the squonk bottle. You may also use non bottom fed drippers as well.
To start out, I would suggest ordering LP with a RM2. They are easy to build and produce excellent flavor. The draw is a bit tight for my preferences and I do enjoy building to lower ohms so the solution for me was to open up the intake a bit with a drill bit. In fact, I now run mine with dual 5/64 intakes. As far as other toppers go there are some very good other bottom feeders available as well. My current line up includes 3 RM2's, a RM3, A VA Cyclone (non Air Flow Control) 3 Cyclone afc's, 2 Reactors and a pair of VA Divo's . All are capable of producing excellent flavor and vaper with minor differences in the builds. There are also some bigger 22mm bottom fed rda's ( Odin just to name one) also available but the problem with those is that you have to remove them in order to refill or change out flavors and batteries as the door hits the toppers.
A Reo is a solid unit for sure and delivers excellent performance with all the pleasures of dripping without having to carry a juice bottle around .
As far as a Grand vs. Mini goes A Grand carries 6ml of juice on board and the Mini carries 3. if you prefer sticking to one favorite flavor for most of the day then go with the Grand. I load my Grand's with my go to juices and use the Mini's for more frequent change outs. I also enjoy my Kayfuns and Mech drippers.
You can expect solid performance and years of service from a Reo with the proper care and minimal maintenance.
Hope this helps AG.