leejp

I, personally, wouldn’t want to introduce another 'elbow' or offset into the mix (a.k.a Head) when you can 'bring the wheelbarrow to the mountain' so to speak. I think it’s easier to put the pump on a platform to meet the existing height of the plumbing then to create an odd network of 45's, elbows, slip unions, etc to bring the plumbing to the pump.

As far as the differences in plumbing supplies at Big Boxes vs the pool store, just make sure you get the DEEPEST unions you can at the Big box. IMHO you'll want any slip union to be as deep as possible (at least 1.5" deep on BOTH sides of the union) to put up with the high pressure of pool water flow. Thread unions should be pretty deep too. Don’t forget the Thread Seal for the pump’s threaded unions. Slather it liberally on the male side of any threaded unions. Just an FYI make sure it’s JUST thread seal and not a sealant/bonding compound for the connections touching the pump. Alternately, you could use Teflon tape for this, but I've found that ALWAYS leaks after the first season.

I am not an expert on this, sort of a Shade Tree Plumber, (four of my uncles are plumbers so I learn a lot from them) I would love to hear from others who are more experienced than I.