First Welcome to AA. I would think again about using CC. It's not good and will give you nitrate problems in the future. also your sand dwelling creatures will have a hard time in it. I would go with just Aragonite sand and also skip the livesand as more then likely it's not live after sitting on the lPS
shelf for so long.
Have you started a cycle yet?
You would need about 100# total of LR
for your tank. It's not set in gold but would greatly help your filtering and you would be able to remove your cannister filters.
As far as the sump, the bigger the better. So go as big as you have space for. An old 29g tank would be fine.IMO
Read over the stickys on this site to get an overall view of it.