alternator upgrade enough?

This is questionable - if you intend to have your alternator rewound this can cause all sosts of problems - it sort of changes the 'powerband' of the alternator and generally they end up producing <12v@idle - this would be particularly disastrous for a stock SLI battery that has seen any use.

Honestly - 1700 hifonics watts really isn't that untenable with a stock charging system - I'd start with a Deep Cycle battery, this is important for many more reasons than running the system with the truck off - Optima or Kinetik are the ideal places to start here- I'd be suprised if you exceed 100-amp pulls on a regular basis.  I imagine that this can be done easier, with fewer side effects, with a proper battery.

Anyway - if you are hell bent on a new alt, look into having one built-to-order instead of simply rewound - lemmie see if I can find a link - but this is expensive - very heavy on the $$$.  You'll spend more on the alt than the amps.  

Regardless of your decision here, the Big 3 with 4 gauge (larger is going to be of limited utility for the short runs under the hood) should certainly be done.