I have been processing color for many years using scratch mix chemistry. The complicated tabletop processing units are not necessary, especially for film (E6 and C41). Use a simple waterbath for the solution bottles. I use 1 liter for both E6 and C41 and save the chemistry to exhaustion. I put the bottles (glass and nalgene) into a dishpan and fill it with 150F water. After about 30 mins the temperature drops through the 100F processing point. If I don't get back to the darkroom soon enough, then I add hot water to take the temperature up to about 110F and wait for the swing through 100F.
Don't measure the bath temperature alone to determine processing start time. Put a good color thermometer--one you can read to within a degree--into the developer, or 1st developer for E6, and a second thermometer into the dishpan water. I use a dial thermometer that is calibrated against the color thermometer. Watch out for dial thermometers noting that they are adjustable and have to be calibrated against a good glass-bulb thermometer.
Load your film into Nikkor reels and put the reels into the daylight tank, stainless steel being my preference. When the developer temperature is about 102F, fill the tank and start your timer. After filling the tank, agitate for the usual 15s to dislodge airbells. Thereafter hold the tank 3/4 submerged in the bath water. Invert 3 times for a total of 5 sec every 30 sec during the processing, and pour out the developer back into its storage bottle 15 sec before the end of the processing time.
Fill the tank with stop bath taken from the bottle that was in the dishpan. Once the stop bath is into the tank, you no longer have to worry about accurate temperature control. Only the developer (first and second for E6) are temperature critical. The fix and bleach, or blix, depending on your preferred formula process to completion and 90-100F temperature range is fine for these solutions.
Processing is a snap once you achieve a certain level of good procedure and you follow it each time you process. I find that 1-liter of C41 is good for 6-8 or more rolls of film and that it's lifetime in sealed glass bottles is about 2 weeks. Ditto for E6, and note that the fixer, bleach, and stop baths can be used for a couple of batches. You need only to remix fresh developers most of the time.
Mixed from scratch, the chemistry for C41 is under $5.00 for 1-liter, and for E-6 the cost is a buck or so higher. The downside is that you need a substantial chemistry stock and this represents a significant investment if you are starting out with nothing. The upside is that you mix all your own black & white chemistry too, and have the ability to mix what you need when you need it. Suppliers are getting to be more difficult to locate but there are some remaining in the business who don't charge excessively high prices. Be sure to do some shopping for your bulk chemical stock, and try to buy in quantities that are appropriate for 50 batches or more. My collection of chem stock has accumulated over about 30 years. These components, for the most part, have indefinite shelf life.
You will also need a good accurate (0.1g) scale, a triple beam balance does well. You need a reasonably accurate pH meter too (0.1 pH unit), and buffer solution to calibrate the meter near pH 10.0.
Developing good technique and maintaining consistent practice is most important. Color formulae are mostly in the public domain now. I am happy to send you my formulary if you mail me with your address.
M. T. Sandford