Reddit mentions of Bayou Classic 800-770 Brew Thermometer

Purchase a 5.5 gallon pot you want but without anything added to it.

https://www.amazon.com/Gallon-Stainless-Steel-Stock-Pot/dp/B000FRJJSM/ref=pd_sim_79_6?_encoding=UTF8&pd_rd_i=B000FRJJSM&pd_rd_r=6PQ2AMFEHC2QZZ0F78MZ&pd_rd_w=34FEi&pd_rd_wg=um6x3&psc=1&refRID=6PQ2AMFEHC2QZZ0F78MZ

Then purchase a weld less ball valve. https://www.amazon.com/Weldless-Stainless-Steel-Valve-Spigot/dp/B0028ZLEE6

and a weld less thermometer
https://www.amazon.com/Bayou-Classic-800-770-Brew-Thermometer/dp/B008FEPE18/ref=pd_bxgy_328_img_3?_encoding=UTF8&pd_rd_i=B008FEPE18&pd_rd_r=222Q1R1CKYW4HFP57VT9&pd_rd_w=m7gkT&pd_rd_wg=pyRcb&psc=1&refRID=222Q1R1CKYW4HFP57VT9

Then purchase a step bit: https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Dlawngarden&field-keywords=step+bit

Make sure it has the correct size.

Then purchase this bit for drilling pilot holes in metal: https://www.amazon.com/Century-Drill-Tool-26208-Cobalt/dp/B004UUFAYW/ref=sr_1_1?s=industrial&ie=UTF8&qid=1481229448&sr=1-1&keywords=1%2F8+stainless+steel+cutting+bit

Drill the pilot holes where you want the ball valve and thermometer, then use the step bit to widen the hole to the correct size.

I have been using this exact setup with an 8 gallon pot for 5+ years and it doesn't leak one little bit. Also you can choose whatever size pot you want, just remember that you should probably leave the thermometer at least an inch or so from the bottom and keep in mind the bottom water will be hotter than the top.

The cheapest route will be to get the parts and build it:

• Kettle: http://www.amazon.com/Winware-Stainless-Steel-Quart-Stock/dp/B001AS90CK
  
  
• Valve: http://www.amazon.com/Beer-Brewing-Kettle-Valve-Weldless/dp/B007B1W0J0
  
  
• Thermometer: http://www.amazon.com/gp/aw/d/B008FEPE18/ref=pd_aw_fbt_328_img_3?ie=UTF8&refRID=1NDJH7J4KN0B7F35H6VR
  
  That gets you what you want for $140 before shipping costs. You could go with aluminum or a smaller pot (this one is 10 gallons) to save a little more, or shop around a bit. I just did a quick search for those.
  
  Just bear in mind that the handles on the cheaper pots tend to be a bit flimsy, so you're better off not moving it once it's full. Make sure you're brewing up high enough that gravity can do its job.