There's basically like six different things, you only need one or two of them
Pre-amp - to put it very basically, it's volume control. It can also be a DSP (digital sound processor) and DAC (digital to analogue converter).
Pre / pro - it's a pre-amp plus processing of surround formats and room correction in the same chassis. Likely also has video processing and other countless features. Think of it as the brains.
Integrated amp - Pre-amp and amp in the same chassis
Amp - thing that drives power into your receivers after being sent an
analogue signal.
Stereo receiver - Integrated amp with a tuner built-in, may also have some video features
Surround receiver - Pre / Pro + Multi-channel amp
Honestly though, you can't go wrong with most quality brands' options. For example the SR7005 will probably more than satisfy you. It seems that the 7005 models (with networking) do in fact have online upgrade-able firmware, although the 5005 and 6005 probably still don't.
If you do in fact have a commitment to something that's made here in north america, chances are you`re going to spend more to get a comparable level of performance. If that`s alright with you look into
-ATI b-stock and outlaw amps
-McIntosh amps and processors
-Classe amps and processors (made in Canada)
off the TOP of my head (i'm sure there's others)
Or just save money and go Made-in-China
