Update to 3.55, you don't need a PS3 or a previous hack installed, to use TNV or ARK, (TNV is the one you want since it has graphic interface of the original PSP for PSP backups and stuff). If you wait to long to update to 3.55 and install the hack (backing up your clean copy of the game to your pc, so you don't have to redownload the game from SONY to reinstall the hack if necessary), then you will lose the opportunity.
Firmware 3.18/3.20 or anything below 3.55, does not offer better playback of PS1 backups, or emulators, those are simply very poorly emulated because the VITA hacks have not progressed that far. There is only one hack game for 3.55 so you can't install both TNV and ARK at the moment, otherwise, SONY has released several updates to the PSP Vita since firmware 3.18/3.20 making 3.55 the better choice of firmware to use for your PSP Vita ... ... ... ... sorry this is very much true, if you miss the opportunity now for 3.55, then you must wait for the next time hack for the next firmware version if any.
(Vitaupdateblocker will only work with current firmware PSP's a few days after Sony releases a new firmware update, for people that have second thoughts about not using the current hack game and hack (last minute purchases LMAO)
otherwise Vitaupdateblocker is good for nothing, use the official sony content manager, then after you install the hack use QCMA the unofficial sony content manager (first you uninstall the official sony content manager, then you can use QCMA with no problems).
https://store.playstation.com/#!/en...icle/cid=UP1024-ULUS10492_00-MCPSPGAMEUS00100
(if you decide to buy this now, then you have to do it online, and then you can browse to your download list from your psp vita on psn and then download it there, make sure you back up the game itself to your PC its the "PGAME" folder, so you only need to download this once from PSN, since you have a backup)