You don't need heavy duty. Heavy duty = more weight, more wight = less you can lift. Your loader will lift only 2700lb if you have 5510 loader and 2600lb if you have 5520 loader. Minus grapple weight. I think, bellow 500lb grapple would work well, no? Commercial grapples are designed for skid steers with 5000lb + lifting power. My 2 cents.
I'm not much of a grapple expert. I agree though, I don't think I need anything crazy here. I tracked down the HLA model he referenced. here it is. It says "light duty" and is under 500lbs. Sounds like it's just an overpriced light duty grapple, no? I would think the worksaver would do just as well for 1k less. What do you guys think on the grapple width? Lots of logs/brush to pick up, some "clean-ish" areas that I can actually scrape into with, more brush once I'm cutting more things down, etc. Maybe I can delay this decision if I'm not buying the grapple as part of the deal.