Hi Randin,
I've got what you have ordered (see my signature) and can tell you it works brilliantly. I originally had 64 gb of ram, but expanded it to 128 gb with specialist ram from OWC. This has lowered my bus speed down to 1066 mhz, but I have not run into any problems yet and can load in a whopping template. Anyway, I digress, your system specs are fine, but I would reccomend 64Gb ram.
My Mac has run a 45minute symphony live and with bounce in place and live audio tracks , with no problem. That was running vsl wind, brass, percussion and string section from vepro 5, as well as LASS, some Berlin wind and Spitfire strings from Kontakt.
I would ditch the slave setup, but keep the old slave machine just in case you want a bigger template, but that's just me, I like keeping complication as simple as possible, but others may disagree with that.
I have found that performance degrades a bit when I have used about 56gb of ram, as the greedy computer wants some too, but 4 ssd's via thunderbolt2 will give you plenty to work with before you hit that limit.
Hope that helps....
Mike.