pretty much the 3 cheapest R4 at teh bottom of Compatbility but teh cheapest, then DSTT higher up on compatbility but not as cheap then theres the AK2istill averages about 20$ but about the best you can get before you start paying 30+ where you'd be getting ones like DSTwo/DSTwo+ or the R4i Gold 3DS
R4 Needs the Stage 2 Launcher but DSTT & AK2i work out of teh box provided your using the latest version of Luma and long since restored Stock TWL_Firm