BAH 1000 from Big Apple has worked for me, but you will still need to use an Acurite to monitor temps, as the temps on the t-stat dial are not always correct. Zoo Med's Repti Temp 500R can be found for 20-25$ dollars verses 40-45$ for Big Apple it just does not have temps listed on control, which does not matter because the BAH still needs to be adjusted according to your thermometer.
I have nine of the two total. If you are breeding, or brumating I would recommend a proportional like Helix. If not the fluctuations of an on off t-stat has worked for all my snakes.