I'm going to make some observations here.
While the illustrations in msg's #26 & #28 appear to be at an angle, they are actually strait lines, IE., the line from 1 to 3 extends strait out from the existing cleanout, relocating the cleanout strait out from where it now is.
Using the fitting you have, in the manner you have them laid out will necessitate additional space for or having to move an appliance to access the cleanout, however it facilitates immersing the piping into the wall in a shorter distance from the cleanout.
There are tradeoffs.
There is a required rise/fall for waste line, so a 6" plumbers level, which is graduated, would be an investment to consider.
I would reverse the 3" street 45, purchase a no hub, hub, hub 3"x2" wye, a short length of 2" pipe, 2" backflow preventer, a 2" street 1/16th bend, a length of pipe to get you into the wall, another 2" street 1/16th bend, the 2" vent Tee, a short length of pipe, a 2" glue trap.The 2" standpipe can 45 out of the drywall and the AAV vent 90's to the drywall surface.
By example, the 3x3x2 wye you have is a hub, hub, hub fitting, the Tee you have for a vent Tee, is actually a sanitary Tee and is not meant to be installed horizontally.
If you are attempting to find all these parts at a hdw store, you might want to save yourself some driving time and visit an actual plumbing supplier.