Well, usually I have a 2.5KW generator to provide power. That's big enough for a 3 or 4 station Field Day setup, yet small enough for one man to lug around. Sometimes gasoline engines are not allowed where I go, so I also have a LARGE storage battery to use in those cases.
For antennas, a single doublet of whatever length I can scrape up (longer is better if you want to work 80 or 160) and I feed it with twinlead and old MFJ roller inductor tuner (Yeah, I know..MFJunk...look around. Not all MFJs are created equal. I've had mine for 14 years and arced it ONCE). For masts, I use camo netting poles (US Army surplus) or steel TV mast from Radio Shack...about 30 feet worth and guy lines.
A small folding table, probably 2 feet by 3 feet and a folding camp chair comes along as well, plus a 12 foot square tarp and four tent poles to keep me out of the sun.
It's been my experience that putting stuff up is not the problem...it's taking it down. So when looking at the setup ask yourself this question: "After I've been up for 24 hours straight, eating nothing but chips and drinking beer, sunburnt, tired, hot and sweaty, am I REALLY going to have the gumption to take it all down????" If the answer is no, then you need to rethink your setup.