as far as a post goes for your lite,all i used for mine was an old steel support post that you use for your basement.
i cut the small end up the center about 8" then welded a flat plate to that and bolted it to the box behind the drivers side.slide the large end over it and drill a 1/2"hole in the large upper pipe and a 7/16 in the inside pipe and tap it.you then bolt this, i welded a washer about 1/2" up the bolt so it would keep it tight.weld another flat plate to the top of the large pipe drill a hole in this to bolt the lite and/or drill a hole for your wires in the top plate or drill the bottom bolt for your lite out and run your wires through the bolt.when the bottom bolt is in, the top of my lite is even with the top of the cab roof.
then slide the pipe up until your lite clears the cab roof and can be seen for 360 degrees. drill another 1/2 and tapped 7/16,that's your setting for plowing. you run your wires inside the pole and they just slide.i have a connector inside the pole so part or all of the post and lite can be taken off. the same bolt is used for both setting,you can use a pin but i think the bolt and washer keep it from ratteling.paint it black or what ever and your plowing snow. JMHO.