I think the heavy style is just a thicker type. They probably look a bigger in the handle. Most jadite sells well regardless. Hope you find some good pieces. I sold some blue and orange coffee cups( fire king) for big bucks
If it's cheap, fire king is almost always a good buy. I've sold lots of it in the past. Some for the promotional mugs can be big money. Also I think the "C" handle mugs are worth substantially more than the "D" handle ones, ebay should be able to help.