ntfs drive.you can buy 32/64gb usb 3.0 drive for dirt cheap these days,but i myself prefer 2,5" hdd sata/usb 3.0 encosures mainly because i have numerous 2,5" drives already,and in my area basic sata to usb 3.0 adapter cable is like 5-6 dollars.and ps3,psX and roms for retroarch can be run from hdd directly,only ps2 and psp iso's need to be on internal hdd.
but first i'd restore everything for the odd chance that somehow you've messed up the settings as i've personally never even heard of dead ps3 LAN and then try plugging only LAN (don't connect WLAN) on fresh restored and reflashed cfw and see if it connects to the net.
edit: you can ftp over wlan,but speeds are atrocious,as ps3's WLAN is mid '00s tech.