OK, here are some more pics. nothing special, but just showing what is going on.
here are the drilling bits i will/have used so far.
on top is the 6' pilot hole bit.

no way to measure in the crawlspace so i had to drill the upper hole in the mantle than pilot hole into the crawlspace from above using this bit. worked pretty well. had to keep the pressure kinda low, so as not to bow the bit, but worked well anyway. i could not find a 6' bit so i used a 2' bit used for installing audio boxes in houses and used 4 1' extensions to reach final length. even this long i only had 6 inches of extra room for drilling.
the other bits are a 2.5" wood hole saw for drilling holes for the 2" PVC. i also used a 1.5" wood hole saw for the 1" PVC return pipe for the sump.
then there are the 3 diamond holes saw that i will use for the tank. a 72mm for the 1.5" bulkheads, a 42mm for the 3/4" bulkheads, and a 1.75" hole saw for the 1" bulkhead.
this next pic is of the holes drilled in the mantle.
hard to tell exactly which line will fit to the tank best yet. where the holes are now are pretty much the only places the holes could be. i had to dodge 2X4 cross bracings and the fireplace itself, so i was pretty limited in hole placement.
starting from the left:
2" hole for CLS inlet
what looks like a 2" hole will actually be a 1" return from the sump. needed to be 2" for inspection purposes. had to make sure it was not going to hit anything.
2" hole for the CLS return, this will go to the two lower 1.5" bulkheads, a little worried about fitting here.
2" hole for the sump overflow. needs to be 2" to act as a vent. the actual overflow will be 1".
2" hole for the 2 other CLS inlets. each powered by a Velocity T3.
right next to that are 2 3/4" PVC pipes sticking out. these were the feed lines from the chiller into the tank. they will now be the Velocity CLS returns. one for each side of the tank. each will cary an eductor.
to the very far right was the water top off feed line from the purifier down in the crawlspace. right now no plans are in the works for this line, but i am sure i will come up with something.
i am still trying to figure out exactly how i am going to run all of those 2" pipes. i am toying with combining all of the CLS inlets into one 4" pipe. i am a little worried about weight if i do that. i do plan on combining them right before they reach the pumps. this will hopefully equalize the pull from the two inlet bulkheads.
G~