standard or low profile?

I agree with the need to stay under 13'-6". But you have to understand exactly what item on your roof sets the current height in order to determine how much it will increase. In my case, it was the shower skylight (which sticks significantly above the roof surface). By going with a low profile unit, total height increased only 3 inches. Very pleased.

If you have a high profile 5er, then a low profile A/C would probably be best. If you have a mid or low profile 5er, the the standard A/C would be fine. As noted above, stay under 13'-6". Lower is better.

Good advice above. Try to stay under the 13'6" standard if at all possible. Bridges/tunnels under 13'6" are shown in the truckers atlas low clearance listing. Depending on your fiver height, that may require a low profile.

You need to take some measurements of your 5ver's height. You DO NOT want to exceed 13' 6" at the highest point. As that is the max height allowed for standard bridge clearance. Based on what you find, will dictate which AC you should install. On my Cardinal, the front and center ones are both 13.5K low profile. the rear one is standard 15K with heat pump.

Look at high efficiency options too, some models have a greatly reduced starting and running amperages.

Do you need a low profile for traveling?