I built a CFC using the information on the DIY sticky, using 20' of copper since that was the longest roll available locally at the time. I can usually have a 6-gallon batch at the desired pitching temperature in about 8 minutes. I gravity feed from the boil kettle, into the CFC, and have a Thrumometer at the end to monitor the final wort temperature. I can then throttle the amount of water to reach my intended pitching temperature - so far the lowest I have been able to achieve was 52°, but that was with the valve fully open. If necessary I could slow the wort flow, and increase the water volume if I needed to get lower. I don't have the exact time available, but I had 11-gallons split between two fermenters in under 20 minutes last night.
Lots of great options available - I'm sure you will be able to find one that works best for your budget and your brewing system. I've been using mine for well over a year, and it freed up a lot of time and effort at the end of a brew session. Good luck!