Yakko, Do you know the specification for the Tech II?
Rather than set your sights on a particular power pack, think about your immediate needs and what your future needs might be. You don't say which scale you are building in, but here's a rough idea of immediate needs:
"N" locos run at anything between 1/4 and 1/2 Amp.
"HO" locos run at between 1/3 and 1 Amp.
Assumingthe locos run at 12 volt (with this voltage at a scale 200mph

) then the output of a single controller should be 6 Watts (VA) for "N" and 12 VA for HO. Both these values are minimums.
Sounds simple enough but..... if you MU two locos then the single controller output needed would be double that mentioned above.
(For the benefit of any newbies reading this, a single controller is often referred to as a Cab).
Now, most power units also have an ac output for lighting, turnout controls and other accessories. Turnouts do not present a problem as they are very short operating duration.
You may be in the early stages of building a layout and may not have thought (yet) about lighted models... street lights, signals, buildings etc. Such lamps (at 15 volts) consume typically 0.03 to 0.04 Amp. 25 such bulbs could need 1 Amp so the ac output of the power supply would need to be 15 VA.
You would be surprised at just how many bulbs can be placed on a small layout (eventually).
You may be tempted to opt for a dual "Cab" power pack if you are thinking of running two trains simultaeneously using block control. Think about it! .... would it not be better to have one "Cab" unit which has an additional (separate) DC output for
a second "walk around" controller??
I hope I haven't confused you my friend, I just wanted to point you in the right direction for the right reasons.
Errol