Had a look at the Tenma - and found out a few things....
First, there is the range - 3 models:
Then there is tracking. Turn tracking on and CH2 follows CH1. Series/parallel connection is OK and appears to be via external connection. The only caution I would make here is - if you want to parallel the outputs, turn tracking on, so that the output voltages stay the same.
Then, these are linear supplies - which means a big, fat, heavy transformer and making sure the mains voltage matches your location - but it will mean an electrically less noisy supply.
FYI: I do not have any experience on the quality or reliability on these.