How and where to weigh grain (best practice) question

[Ish200]

I am in the planning stages of a small distillery and I am looking for thoughts on where and how to weigh grain prior to mashing in.

Assumptions:

1) Lets assume a bourbon mash of corn, rye, and malted barley (ratios are not important atm just the fact that we are using three individual grains) 
2) The grains will be coming out of individual outdoor grain hoppers and moved via flexible auger system.
3) There is only one mill that all the grains need to go through (roller or hammer is not important atm, assume all grains are milled on the same setting requiring no changes to the mill between grain)
4) The objective is to have an accurate amount of each individual component go into the mash following the milling process - ex: if the recipe calls for 100lbs of corn we get 100lbs of milled corn in the mashtun
5) we want to avoid physically lifting any containers of grain

Would you:

1) Weigh each individual grain in some sort of suspended hopper scale before being milled? - ex: fill the hopper with 100lbs corn and use gravity to feed the grain into the mill, then fill the hopper with the next grain at the given weight

2) Weigh each grain after it is milled by milling into a container that can be placed on a floor scale  - ex: run the mill with corn until the collection vessel for the mill reads 100lbs then switch to the next grain

Any other thoughts on how to simplify the weighing process would be appreciated

Thanks!

[Thatch]

We are both a malt house and a distillery.  We use a flow scale to measure the amount of raw barley that goes into our steep tank to make malt.  It's fed by a tube conveyor but could easily be fed by a auger.  We are quite please with how well it works and how rugged it is.  Brewers mount this right above a mill.

http://agtronix.com/flowscale.html

[Ish200]

Thanks Thatch! I was wondering if there was an alternative to putting everything in one large storage bin for taking weight, this looks like a great alternative!