All the brands mentioned so far are quality units. Most of the companies are still in business as well so you have a resource for manuals, parts, service, etc.
To those mentioned I'd add Ettco, SPV, Jarvis, Snow, Wahlstrom, and Nikken-Coventry.
I just bought two different tapping heads. A Swedish made SPV tension/compression type to cover smaller taps and a Supreme Versatapper with capacity from #10 to 1/2".
Paid $112 shipped for the Versatapper and ~$80 for the SPV.
I'm thinking the Versatapper will be used most of the time and the SPV reserved for the smallest taps. Hope it's sensitive enough to not break these tiny taps.