I think perhaps you look at the three models. Search which of them allow any pre-amp out to cater for your future upgrade to more powerful Power Amp if you want to upgrade years down the road.

Then you have to listen to each model, if possible, bring along you speakers there and listen to all three of them in single session.

Chan, to audition the amp, here's my advice.

1. Make sure they neutralise the equaliser. Some AV Amp comes with loudness which enhance the bass and trebles, it is not the real sound you want for audition. So make sure they set it to neutral, or Zero. I made a mistake once.

2. Bring along music CD that you know best from your own home. If possible, bring along a vocal CD, Music CD - both instruments and Rocks ( i also bring along a classical CD too if you have it), and then a movie with lots of noise, actions, and test the sound separations. Don't use their subwoofer. Just your 3 speakers thats all.