Which pot for cooking?

Looking for a pot to handle larger batches.
 
I plan on getting the handyfiller, so it would be great if i could hook it up to that, but looking for recommendations.
 
Would i be better off getting a pot and adding an external thermometer, or a brew pot - similar to beer making that have the temp gauge on the front with a ball valve for flow?

How big is your operation going to be? Large is a very relative word. This answer will very much impact the way you go about purchasing a pot for larger batches. 
 
Taking a wild guess that you are starting out relatively small, something along the lines of one of these will be more than sufficient:
 
http://www.webstaurantstore.com/2737/stainless-steel-stock-pots.html (FYI, this site is my favorite site for buying utilitarian kitchen tools)
 
You can get up to 100qt stock pot, that is 25 gal. of sauce, 3200 ounces, or 600+ 5oz woozy bottles. The problem you'll problem have there is that you'll need to get a standalone burner to be able to handle something that large. Don't think you'll be able to put a pot that big on your stove and even remotely be able to work effectively. I have a 10qt pot and between my stove and exhaust fan I am just about tapped out with what I can effectively do without killing people in the house with the smell and being able to control heat. 
 
Once you get larger than that, you need to look into getting a food manufacturing kettle with dedicated services, tilting design, etc.. 
 
http://www.foodservicewarehouse.com/equipment/steam-kettles/c3791.aspx
 
As you can see you are getting really pricey. If you are installing one of these you are going to need a facility to put it into. And if you are doing that, go get yourself a commercial kitchen consultant and not just some dude on an internet forum telling you what you need. 
 
Hope this helps.