Just slow down guys, there was some website that can install the hack AND sd2vita plugins directly to a PSV1xxx with low firmware. Maybe there are a website that can still do the trick, but most we know went offline already.
Currently, for a psv1xxx use IMCunlocker to format the internal ur0 to make it work like psv2xxx and do not require SONY memcard to hack again (just in case you intend to rehack, lost your SONY mem or your system have major failure/corrupt that reset your settings).
If you are a psv1xxx user, just reboot while holding L you can test how far you can go without a SONY card when in trouble. Reboot again to return everything to normal. Have fun.