I want either this one or this one in the longest length respectively. I've got their speedball and floor/ceiling (double end in Americanese) bag. Super nice leather and quality workmanship. I do 1000 punches on each each day and 2000 on each on weekends. That's for conditioning. I also mess around with broken rhythm combos etc on weekends. I don't wear gloves and they've calloused my hands, but no broken skin. So I'd be pretty happy with their heavy bag I imagine.
AUD$500 == US$366.618 today. I use xe.com.