Suburban 2nd Row Shoulder belt help

[swissarmychainsaw]

I need to be three point seat belts in the backseat (2nd row) of my 1973 burb.

A trip to my local junkyards did not provide what I need, so I'm considering buying new aftermarket 3point belts.

Who has done this and what did you buy? Did you like it?

Looking at LMC truck (though they sell the same for front and rear, which is suspicious to me).
Seatbelt Planet
Retro belt

Any help? Need to get my kid buckled in!

thanks,
Nick