The amp is needed for thermocouples with the U3. If you use a silicon type sensor (e.g. LM34) instead, then you don't need an amp.
We had suggested the LM34CZ or LM34DZ from Jameco for $5 or $2 each, or even order some free samples from national.com. Then use epoxy, plasti-dip, a metal tube, or whatever else works to make a beer-proof probe.
Pump control was also brought up, so we suggested an SSR from Jameco also. The 176719 is only $20 and handles up to 40A @280VAC. If you don't need so much current capability, you could look at the 176698 or 175214.