We have a 6,000-lb lift and it handles anything we need. If you re operating on gravel, you ll have to go with pneumatic tires. The upper end of that size range would do best while giving you the tight-quarters ability. Three stage mast and side shift are commonly demanded features and make the machine more useful. We have had good luck with machines from a reputable lift dealer that are 2 to 3 years old and have 1000 to 2000 hours on them, have been well maintained and don't look beat up.
Older machines are harder to get parts for.
We bought our first auction machine last winter and ended up putting a new motor and transmission in it. Talladega Machine Sales is a good place to look at both machines for sale and comparable values. Ask around for reputable dealers in you area and get three proposals. Once you buy a machine, don't forget preventive maintenance and some sort of operator training program. Propane is fine indoors for the little you will probably be running it.