Maybe I am missing something here, but you know that after you pick a point you can just point your crosshair toward the direction and just enter the number of units that you want to go. Of course, ortho takes care of 90 degree increments, but you can set your polar tracking to increments in degrees that you use most often. Right click the Polar button below the command line to set your prefered angles. Set it to 10 degree increments or whatever. If there are angles that you want to use that aren't listed, just hit the "New" button, enter your desired angle, and then pick it from the drop-down list.
Go to Options>Drafting>AutoTrack Settings, and make sure the "Display AutoTrack tooltip" checkbox is checked. Now, after you pick the Line command for example, just point in the angle you want to go, and a tooltip will tell you which angle that you are "snapping" to.
Of course, you will have to make sure that "Polar Tracking" is on.
Flores