Do you want to fry relays or use them for switching purposes?
A 5V relay won't last long being supplied with unregulated 12V!
That page also contains an offer of 12V (10A/125V) even cheaper (US$5.99 instead of the 5V type for US10.99).
Also it pays to use good brand relays for reliable function over a long time period. I use only FINDER relays.
BTW, I have redesigned your circuit for a greater span of presettable switching temperature, including a 12V stabilized power supply and a stabilized voltage reference.
The PCB layout is single sided with one wire jump to force circuit ground to go off the smoothing cap connected to the regulator output pin.
Board dimension is: 3.35X3.025".
Regards
Boncuk