Ahh thanks for editing the post to be more descriptive OP. Trying to stay around a 4K gennie might present some issues. If you plan on running the Ac during the summer, it's a huge consumption and other things like the electric side of the HW Heater, That alone will pretty much take all a 4K can put out.
You can shed some consumption, by switching the HW Heater to propane and turning off the electric side. That frees up from around 6-9 amps.
If the gennie would be used mainly during the winter, not using the Ac or the electric side of the HW heater, would free up alot of the load. Then that spare current can be used for one or two small space heaters, as well as having enough to run the blower motor on the propane heater.
So it really depends on you're planned uses and anticipated needs. I do think in the summer you would be hard pressed to be able to run much more than the Ac on this though. So there is no real set answer on what is best.
You definitely need one with a good muffler and spark arrestor as mentioned. Some states require the arrestor.
Here's a decent priced gennie from Home Depot. It has the same Honda car muffler as mine. But with 500 more watts than mine.
Sportsman 4,000-Watt Portable Generator $329.00
http://www.homedepot.com/p/Sportsman...4065/100637527
