Need help finding rear brake kit

[Fastrun72]

Hi... I just installed my new Moser 12-bolt rear in my 1972 Camaro with Hotchkis leaf springs. I have the BIG Ford bearing Flange with 2.5" offset.
I am wanting to install Willwood's 13" Black SL4r #140-9219 kit with parking brake on 18" Rushforth's.... I was told by a Willwood tech that this kit will not work due to my staggered shock set-up and they have nothing for my application.... Is this true??? I have heard that there shouldn't be any issues with the shock positions and would like both calipers rearward facing. Does anyone have a similar set up on their second gen. Camaro or know what options i might have??

Thanks in advance, Jim