Howard,
That is the same cooler I am using. It has some big outlets and inlets. You will have to step it down somewhere along the line. I ordered mine large enough to fit the rear vents on either side of the exhaust. Am doing the oil that way as well. I am using the Mocal pump with mine. The spray bar setup can be had from Aircraft Spruce at:
Fittings from Aircraft Spruce
These may be a little small. They look like the same ones in the pic. You will find that the number of holes selected in the manifold is odd to the number you want. Either plug the extra one(s), or do like I plan, and that is to cool 2nd, 3rd, 4th, and R&P. First would not be used in any racing situation, hence not needed to cool. Of course you could always make your own.
There should be enough space for air to get to the coolers unless you have the rear bottom panelled. If you duct air up into the rear clip you may have a problem with too much air pressure under the clip. Easier to add a puller fan. That way you keep air pressure to a minimum. I am including a pic of how I set mine up, and one I had a pic of. Don't remember whos ride it belongs to. I am changing the orientation of the cooler to the lines at top. Solves all air problems. once the cooler is filled it will not affect the level of the oil in the box. If the two(box and cooler) were vented to air then you would have a situation that they would seek their own common level. Since the cooler isn't it is not a problem. Your storage tank if used could be mounted anywhere. Just make entry at the bottom and exit at the top. Circulate and top off the trans to whatever level you want. Just remember with the trans flipped it does affect the fill hole or full hole (whatever??)
Bill