I only plan on buying 1 rod for all my cranking needs.  Would I be best off  by getting a 6'6"M, 6'6"MH or 7'MH.  It is the Browning Silaflex rod I am looking at.I would guess that 80% of my cranking will be from 0-10'

One rod just won't cut it. I really can't cast shallow cranks with the same setup that I'm using for DT10-16s.   But if you want just one rod for most of your crankbaits, I would suggest a 6'6" or 7'0" M baitcaster  with a med action tip.  A specialized fiberglass crankbait stick would be the way to go.  

6'6ft Medium action

7' MH is wat I use for all of my cranking

7' MH. My first crank rod was M. Didn t have enough muscle for the bigger cranks. Had to upgrade.  Go with the MH

7' MH. My first crank rod was M. Didn t have enough muscle for the bigger cranks. Had to upgrade.  Go with the MH

That's fine if he's only going to throw big cranks, but he wants one rod for all cranks. In that case a M would better serve him.

I use med and med light for anything that has trebles. Stiffer rods will eventually cause you to lose fish after the hook up.

7' med action.

I had a Silaflex. It's really heavy and will wear you out if cranking all day. Good action for a fiberglass stick; just heavy feeling.

If / when you can upgrade, look hard at the Shimano Crucial CB rod. It's a special graphite blank mader for CB's and at $130, it's a great value.

For most applications I'd go 7'0 M action rod.

The longer rod will let you cats longer meaning max depth.

For the depth you are saying you will be fishing (0-10').  I would recommend a 7' med action.  My personal favorite is a G. Loomis 843 crankbait rod.  I also have a 6'6" CBR 783 but I like the 7' better.