While you may find a rack that will accommodate the rest of your gear, I know of no ready-made rack that will properely accommodate the PS Audio P1200 without turning this really deep component sideways.
I work as an industrial designer, and had plans to design a custom rack that would take into account the considerable depth of my own P1200. Thinking about it though, I'm not sure I really want a rack that is 3 feet in depth.
As a possible alternative, you could try the following very simple, very economical project, which will result in an absolutely stunning piece of furniture:
A common (in the U.S.) furniture mover's dolly (available for about $20.00 from Home Depot... has the exact same footprint as the P1200); get one and make (or have made) a nicely finished shallow box that will fit over the top of the dolly. Leave only the bottom open. Place the box (open side down) over the dolly, making a sort of rolling plinth (sides of box should clear floor by about 1/2 inch with full compression of listening room carpet fibers under a 150lbs vertical load). Place your P1200 on top of the rolling platform. Obtain 5 plain hockey pucks from a sporting goods store, and place them (evenly spaced) on the top cover of the P1200, then place a simple custom cut, thick (I used 5/8" thick) rectangular piece of glass over the pucks (have glass cut to the same dimensions as the top of the rolling platform... I would not go less than 5/8" on the glass thickness, simply for reasons of visual weight... the results will scale better with thick glass ... also, have the edges of the glass polished). In my case, the glass hangs over the P1200 just enough to offer some degree of protection to the aluminum.
Voila!.... you now have a unique piece that is not only functional as a low table, but puts in evidence the strikingly beautiful design of the P1200. The power cords that flow from the rear panel may be a consideration.... I say as long as they are out of the common foot path, arrange them nicely, and leave them for all to see, as most audio power cords these days really are their own little works of art.
This project will allow some necessary distance between the P1200 and the rest of your gear.... remember that the P1200 has 2 very large transformers (3 in export models) that generate substantial electromagnetic fields, and need to be kept no closer than 3 or 4 feet from sensitive front end gear, especially turn tables. I have mine centered between the listening position and the speakers.
According to PS Audio, the P1200 does not benefit from extreme measures with regard to resonance control, (they in fact recommend placing the unit directly on the floor), so the above solution should give up nothing with regard to sonic quality.
When it comes time to move the 150lb+ P1200, you will be very happy for the wheels.
Being a minimalist, I prefer the simplicity of a clean piece of glass, but as an option, I could see having a second piece of glass cut to the same dimensions, then sandwiching 2 of your favorite album covers, or a large photographic print of your favorite artist (movie poster?)between the sheets of glass.
Hope you found this of interest.