We had a few of the Sunforce inverters in the vans at work. they worked good for a while. The guys were rough on them though....occasionally wet from rain/snow, dusty/dirty, banging into them with equipment, constant overloading, etc. we use a commercial inverter now, built for abuse, about 7x the cost.
anyway, if you do the math, you'll need a larger cable, #2 @ 3meters & 90Amps, to keep power losses down. That's for the 1000w inverter nearly maxed out. If you keep your loads at 500 watts max, you'll be ok with #4 wire with a loss of >2%.
2000 Cherokee 29BH with 6V batteries, LED lights & 400 watts of solar power, flipped axles and raised. 2007 Tundra 5.7L DC-LB with lots of mods. C-co, 8/158th AVN Maint.