Sorry for double post, if anyone is still interested, i managed to compile the latest psikyo core for the FBA4PSP emu. AFAIK it was never released as binary. This core runs Striker 1945 and a few other psikyo games, game list is included. You can also see the games emulated here:
http://www.system16.com/hardware.php?id=810&page=1#2321 It plays with 1-2 frameskipping, i will try to disable caching to gain a few more FPS, but no promises. Any active PSP emu developer, feel free to help.
https://transfer.sh/iu1av/psikyocorecached.zip
EDIT: Here is the eboot.pbp with caching disabled, it means it has better FPS, you can use 0-1 frameskipping with Strikers 1945 and Gunbird. I havent tested but this probably only works on slims though. Use the cached version if you have fat.
https://transfer.sh/9nKtP/psikyocorenocache.zip
EDIT 2: I can compile no cache (faster) versions of other cores too if someone has still interest in FBA4PSP.
P.S. Use Strikers 1945 (Japan, unprotected)