KOF94 is not a CPS2 rom, the rest are, you just need to grab the qsound sound rom as it suggests
Q-Sound rom file it is named qsound.zip, just pop that into the roms folder
KOF94 crashes both 0.151 and 0.152 of MAMEUI
EDIT
KOF94 seems to work in MAMEUI 0.150 and works in MAMEUI32 0.151 and 0.152
You can get MAMEUI32 from
http://www.progettosnaps.net/mameui.html
EDIT:- posted that as a bug report on the MameUI forums
EDIT:- It seems having cheats enabled for that game in MameUI (the 64 bit version anyway) makes that crash, so if you really wanted to stick to the 64bit version just disable cheats (Options > Default Game Properties > Miscellaneous tab, untick Enable cheats )