you don't need the limited.... the normal will do fine.. the limited is only good if you run 2 different firmwares... you also need the downgrade dongle... follow these steps and you will be fine...

install flasher
read nor chip
check file
patch file
flash back to nor chip
power on the ps3 and wait for the missing hdd message to see it if it working
remove flasher
put the hdd back
put in the dongle(this is the only time you will use it)
power on(power then eject) it will beep and turn off
now ps3 in service mode
remove dongle
put desired firm(must be 3.55 rogero) with the proper lv2diag.self on usb
plug in the usb in the ps3
power on ps3 and it will do the rest
after its done it will turn off
remove usb power on
if everything went fine you will be in the XMB with red box saying service mode
turn if off again
put the other lv2diag.self file on usb
plug usb and power it on
after all this just remove the usb and power cycle the ps3
congrats ps3 is now downgraded lol
d(^__^)b