hi friend!
so, you mention a budget: that's totally understandable, but keep in mind that sacrifice in price leads to sacrifice in quality/reliability which can cause problems. i started out using Jumpstart thermostats for a few years and eventually saved up the money to go for the Cadillac of thermostats: Herpstat. i also have a VE-300 thermostat which is just as reliable, but a different brand.
for someone with a budget, i usually recommend Jumpstarts, but i need to HEAVILY EMPHASIZE that Jumpstart thermostats are KNOWN to fail; it is NOT an "if" but a "when." suffice it to say that i've successfully used a Jumpstart thermostat for almost 3 years, but i NEVER allowed it enough time to fail on me; i bought a Herpstat as soon as i possibly could.
for the heat lamp: if the room the enclosure is in has a stable temperature throughout the day (i.e. no more than a 3° fluctuation in either direction) you can get away with using a rheostat for the bulb. rheostats do not use a probe to read a temperature like a thermostat, and can only be set by a dial; this means the power output will stay the same, whether it's 70° or 100 °F. in terms of reliability/set-it-and-forget-it use: thermostat > rheostat.
i hope this helped!!!