I am impressed. For someone who's never had snakes before, you're off to a very good start. Flexwatt, thermostat, separate tubs.. You must have cracked down on some hardcore research. Glad to see someone who does their homework!!!
The pic in the first post isn't working, though? Very curious to see a pic(s) of the lucky little guys!
BCIs are very enjoyable... I just have a subadult male currently. He's a troublemaker, but so sweet. You've gotten some good advice thus far. 88-90F hot spot is standard recommendation, up to 92ish is fine until you can comfortably say they're clear of RI risk.
If you can get larger prey, I agree with the recommendations to get a bit bigger prey item than a fuzzy. I haven't seen a pic of the babies, but if they're as big around as a jumbo sharpie, they're big enough for at least a hopper/weanling. IIRC, Colombian boas are generally born large enough to take hoppers from the start.
Keep an eye out for more babies while you're out and about. Hopefully it was just the pair that was dumped, but you never know with people these days.