This may reach the OP too late but here goes. As a frame of reference, I use a DSS plate with either a DSS T-17 wing (tropical with an Al 80) or an Oxycheq 30# wing. And a regular hog harness with crotch strap. No STA required with the DSS or Oxy wings.
When I first bought the item, I was concerned the plate would be uncomfortable without the padding. I find mine very comfortable with no pad. I would tend to skip the pad, at least for now. (IMHO, It is better to start simple and buy something later to fix a real problem you know you have than it is to buy something now thinking it might be a problem if you don't).
The hog harness is simple and, at least for me comfortable. More than anything is is adjustable. And cheaper. IMHO, I would start with the hog harness. (IMHO, It is better to start simple and buy something later to fix a real problem you know you have than it is to buy something now thinking it might be a problem if you don't).
I also think the REC-EXP wing is a bit large for singles. It it will be more difficult to vent and less streamlined, when using a single. I am a huge fan of buying a wing designed for singles and, when the time comes, buying one for doubles rather than a wing dual use wing.
I am a big fan of DSS (great products and service), Oxycheq (their wings), Halcyon (all but the cost) and the Hog brands looks promising as well. I also really like plates/wings that allow you to use a single without a STA (the STA moves the tank further away from your back and, IMHO, that is sub-optimal). Still, I might go dive-rite if that was local brand and getting others shipped was cost prohibitive.
By going with a regular hog harness, no pad and the travel wing (assuming that meets your lift needs) you probably knock $100 off the price. Set that aside to help pay for the doubles wing when the time is right...