Unless they're offering a significant package discount off that price (say 25%), I would buy the Halcyon wing and SPG you want from the LDS, and SB or eBay for the plate, harness, STA and cam bands, and weight pockets. That's assuming you want local warranty service on the stuff that could go wrong and be tricky to buy used... I've had good luck with used H wings myself, but YMMV.
For the Atomic Z2s, which are indeed great regs, it depends on how much you care about warranty coverage and whether your LDS is worth trusting for the bi-annual service. Personally, I'd say buy em used, have em serviced, and go on your merry way. The only Atomic product I've ever needed warranty service on has been my Cobalt, and I have no doubt that I would get a fair shake paying for repair work on an out of warranty used reg if I ever needed it (probably wouldn't, though, hence the advice to skip the warranty). But if you want your regs covered, buy them new from the LDS if they'll offer a competitive price AND you trust them to service your regs. If not, buy them new from an online Atomic dealer and ship them back to Atomic or ScubaToys or whomever you do trust for service when needed.
All of this is assuming that the link you posted is related to a brick and mortar LDS you would use. If that just happens to be an online retailer you found, keep shopping because it's brutally overpriced. And the ABC pockets shown are a generation behind what H is offering now.