Canokie, There are many variables that can determine whether you need a vent. If I was going to use a vent on a cold frame I would use one of the heat activated types. I will attach a link that shows what I'm talking about. Many say they work well. I have 2 that I will put in my greenhouse if I ever get it finished. On my lean to I'm installing auto operated louvers and fans thaI have never had heat issues with either of my cold frames. I keep a hi/low thermometer in each. My lean to greenhouse has way more heat issues than my cold frames ever have. On mornings where the temps have been as low as 28 degrees F I have propped the tops open 1-2 inches. This has prevented over heating along with preventing the plants from freezing. The cold frame with the tinted glass is easier to control the heat in. If I leave it closed and the temps reach 80 the max in the cold frame will be upper 90's. I have never seen the need for vents on my cold frames so far. I also dug down 6 inches deep inside the cold frame. This helps to moderate the temps also. Another thing you can do if you don't have tinted glass is to lay a shade cloth over the glass. Jay Here is a link that might be useful: Greenhouse vent

"...you will probably also need strapping or connector plates." Strapping nd connetor plates help hold the studs to the bottom plate, the top plate to the studs, and the rafters or trusses to the top plates. Nails in tension (withdrawal) have very little strength, nominally zero in many places. High speed winds do not just produce side loads but also produce lifting forces. Wind striking the side of a house turns up and down, the upward winds then produce a lifting force on any roof overhang, just wind swirling over a roof and dropping can produce lift on the roof structure similar to the lift on an airplane wing. If you think about typical house construction it relies on a few fasteners to hold position and weight to keep things down. Racking forces are accounted for, and downwards loads, but not lifting forces. By adding straps and connectors nails are loaded in shear instead of tension. The structure has more resistance to uplifting forces.

For any lurkers, I found my answer and I'm going to frame it so it looks like this: Here is a link that might be useful:

The standard throat/frame size of all residential door and window frames is 4 9/16" but 6 9/16" is always available for a small additional cost. If the store wants too much for the larger frame depth you should try a supplier that sells to professionals. Since an inswing door frame is set to the interior face of the exterior wall, the big issue is the exterior projection of the threshold. If an extension is offered you must be sure it is adequately detailed and attractive.