There are several!
For starters, you would probably prefer a wing with between 30 and 40 pounds of lift, as any more would make the wing to big and floppy, and would do its best to put your face down in the surface when fully inflated.
It should be a wing designated for single tanks (relatively narrow), which means you will need another wing when you decide to dive large twinsets (small twinset may work well with a singles wing)
The wing should not have any bungees, as those are really bad if it should start to leak.
I prefer circular wings, and have been using the Halcyon Eclipse 30# quite a bit, and enjoying it very much! I also have a GolemGear Ring-wing, which I unfortunately have never dived (long story), but it looks really nice, and is perfect if you get a backplate with an integrated single tank adapter such as Golem Stream (which unfortunately is not very suitable for twinsets)
The brands I personally can recommend is: Halcyon, Oxycheq, DTD/DirZone, GolemGear and Agir. This applies to wings, backplates and single-tank-adaptors (STA).
The type of harness is another matter. I use a Hogarthian setup, which is a single-length webbing without any quickreleases, almost like a backpack, but this is a matter of what you prefer, unless you plan to do a course with GUE, then it is a requirement. Still, I like not having any weak points...