I would say the easiest to keep and breed are smaller species of genus Tockus (like erythrorhynchus, flavirostris, deckeni, nasutus). And among larger species, genus Bycanistes (bucinator, brevis, atrata) is ok, also A. malayanus.
I'm very interested in hornbills in aviculture. Are there any breeders of the larger Bycanistes other than zoos? I'm particulary interested in Bycanistes albotibialis and Bycanistes brevis. I see lots of Von der Deckens, African Greys and Red Bills for sale on softbillsfor sale.com. If I could have any species of Asian Hornbill it'd either be a pair of Blyth's (Papuan) or Knobbed. Asian Hornbills are so hard to pick a favorite!
I also love the private aviculture community, it's so hard to find other aviculturists in my area. In response to your comment, I don't see any albotibialis in the US market, I do see some older brevis from time to time, but no juvenile or breeding individuals, it's so cool being able to talk to other aviculture enthusiasts, and I agree it's so hard to pick favorites with the Asians.
In the states, there's not much for larger hornbills, sadly. Von Der Deckens is the best represented, African grey and red billed are around and breeding in smaller numbers. The two yellow billed species are around, but are sadly becoming increasingly less common. Pipping are respresented and there should be a decent number thanks to more recent imports, but little to no breeding has occurred thus far. Trumpeters aren't common, but aren't rare either. Silver Cheeked are also around, but bred with less frequency every year. There are a very small number of non breeding Black and White Casqued, along with a handful of Black Casqued and Yellow Casqued. There might be a very small amount of breeding going on, but if there is, it's very minimal. For Asians, there is a small population of both Sulawesi and generic tarictic hornbills, fortunately both populations do have some degree of breeding currently occurring. There is a small but steady population of oriental pied. For larger birds, there is a small number of Blythes Hornbills, including one breeding pair and even some recent imports. A handful of wrinkled, but next to no breeding AFAIK. A few male rhinoceros hornbills are kicking around, and one or two rufous hornbills too, surprisingly. All are older and non breeding. There are also one or two pairs of wreathed hornbills as well, and possibly breeding too.
Have you just kept a running tally from your personal research or is there a public database with this info, I've seen a good bit of import activity particularly around rufous, and like you say Blythes have also been getting some new blood from the Solomon Islands. I'd love to see some more hornbill species come around to the states in my lifetime, and it seems for the most part imports are where that's going to have to come from as a lot of our private breeding populations outside of zoos have stagnated somewhat.
Europe has quite a number of hornbills in private hands, highest density of them is probably in Benelux and Germany. They are not popular here in Czechia, but some breeders exist. Few pics from probably the biggest collection here (old, this collection grew since).
Knobbed hornbill chicks - 2 of 5 currently growing up (all from a single breeding pair that breeds annually), private collection, Czechia The breeding pair aviary
