Q,s about Carver tfm 15 cb Amp vs. Carver m 400

Im looking to buy either the carver tfm 15 cb or the carver
carver m 400 to push some old infinity 8 ohm x 2 whats the difference? Whats Better?
If the m400 is not a "t" series,the tfm 15 will sound a lot smoother and more pleasant.