For show purposes, the ideal weight of a Holland Lop is about 3 pounds. The Mini Lop's ideal weight is 5 1/2 - 6 lbs, so yes, the Holland is much smaller.
In my rabbitry, I have Holland Lops, Mini Rex, Netherland Dwarfs, Jersey Woolies, and Harlequins. While the personality of a rabbit is partly who its parents were, and partly how it was raised, I find that the HL's and MR's seem to be more likely to be friendly than the ND's. Don't get me wrong, I have had some really sweet Dwarf's over the years, but they frequently are a bit more hyper than the slightly larger breeds.
I'm sorry, but I have a long-established prejudice against Lionheads. The ones you see on the websites are adorable, I agree, but IME the vast majority don't look like that. As has happened with a lot of breeds, the early popularity has vastly outpaced the ability to breed quality, so an awful lot of people are breeding poor quality animals because that's all they can get (or they don't know/don't care what the breed should really look like). Perhaps it's the local breeder(s), but 9 times out of 10, when I get a call from someone who has a rabbit with a health problem, the sick rabbit is a Lionhead. (Most of the local vets don't see rabbits; those that do charge an arm and a leg. Breeders and the rabbit rescue group field quite a few calls from people who don't know what else to do). Other people have told me they don't have that problem, IDK.
If you have a source for quality stock of sound health, great, but don't get suckered into buying something just because "it's a Lionhead!" or whatever.
My advice would be, do your research first. Figure out what your market is, and what is available. Get to know people who have the breeds you are looking into, and pick their brains on what breeds or even bloodlines will work for you. I have a friend that breeds nothing but fall-out-in-your-arms friendly rabbits of 4 different breeds. Anything of hers that isn't show quality still makes a quality pet; just saying an animal comes from her lines carries weight with breeders in this state!