A153 ssbc conversion?

thanks for all your responses.
I was aware a different length rod was required on the disc conversion.
If l decide to replace my factory 7" dual diaphram booster (I believe it was made by midland according to the service manual-- are these available or is rebuilding mine the only option? I have seen combination master/booster with brackets available which look similar but again claim to require modification to work on factory power brake cars. I believe a template would be provided. Last thing l want to do is modify my firewall to work.
Everything being sold these days seems so vague on fitament and specifics.
thank god this site is available to help us out.
Being up here in Canada does not help much. Exchange rates/duties/brokerage/shipping certainly add up.