Beemer Boneyard has a complete kit for the 1150GS, includes the 90 deg.
New CPC Chrome Plated Brass Fuel Line Quick Disconnect Set For R1150GS ADV Bikes Only
CPC makes the "OEM" plastic one too, but BMW got it wrong, they should've used the metal fittings. This is a known issue, my buddy's GS plastic connector also cracked and drained the tank.