IMO, there isn't much of a performance difference betwen the base civic SI and the mugen version. I would definately look at the civic si. I would drive both to see what you would prefer.
Current: 10' E90 Jerez M3 DCT
///Mods: Xpel front clip wrap, Nokya 2500k H8 halos, matte grills, IND reflectors, scoops, MS drop-in, MS track pipes, Dinan exhaust, 240E, ESS tune, BBS CHR, s04 255x35 295x30, KW Clubsports, ceramic pads
Retired: 08' E92 328i JB 6mt 212 rwhp 190 rwtq