Ah... I'm not sure how to answer. There are so many i3's. And Prusa has his own fork of Marlin for his current i3's.

But if you want to bring up a generic i3, you want to do it using https://github.com/MarlinFirmware/Marlin/tree/RCBugFix Be sure to turn on the UBL bed leveling. It is the Cat's Meow of Bed Leveling! Also, turn on the Z-BabyStepping and DoubleClick_for_Z_Babystepping (in Configuration_adv.h). You will really like that set up!

(And you don't need a Z-Probe for the UBL Bed Leveling. It can be setup with just a Z End Stop. But it will take you an extra iteration of G26's and G29 P4's to get the mesh perfect without a Z-Probe.)