I have a 7,000 lb. trailer and it handles my JD 4200 with FEL and BH just fine. I have a 22' diamond plate floor and have no problem carrying my finish mower on it, too. I think I could add my box blade without any difficulty, though I can't imagine the job I'd have needing the BH, finish mower and box blade. /w3tcompact/icons/smile.gif
I'm not saying a 10,000-12,000 lb. trailer wouldn't be nice, but 7,000 is all I need and probably all you need, too. You should be able to just do the math by adding the weight of your tractor, attachments and the 7,000 lb. rated trailer. If the total is 7,000 lbs. or under, you'll be within the rated limits. Personally, I wouldn't spend the money for a 10,000 lb. trailer if that total was 7,100 lbs., though. /w3tcompact/icons/smile.gif