Working good now, it also helps to monitor the glycol cycling.
So I used the pigtails I linked to above, and then I used some wire nuts and made the connections between the two SSRs. It all worked out very well once programmed and wired correctly.
It was nice to be able to use the old FTSs power supply, and then I used the cooling only FTSs power supply to power the brewpi. Nice that I didn't have to by anything but those pigtails to recycle some old parts.
I'm using wifi on both the pi and brewpi, and that has been performing great as well.