You can parallel both, but to get more than 20amp current out of the standard 2000i you need a special add on kit. The Companion model has a 30amp twistlock plug (electrically only capable of 26amp, though), Standard model only has 20amp standard plug, to get more current from parallel standard model ones, you need a special breakout box with 30amp plug (can be built for about $20 in parts).
If this is only to make coffee and charge batteries, I would just get a propane coffee pot and some solar panels ;) that's the route I plan on going. Though there's sure times a generator would be handy, so I certainly get it.
EDIT: I should add I do not own one, I have just heavily researched them.