If you have space available, I'd highly recommend against benchtop jointers and look for a stand type model. Keep an eye on CL, good deals can be had and you can likely find a really nice 6" jointer for close to what you're looking at for a bench model.
I haven't looked at the bench models in a long time, so I don't know about the knives. Generally speaking, HSS comes in different grades and the better quality knives are quite durable. A good 6" jointer with HSS should stand up to the kind of work you're doing.
The wood you're getting is a great find. It is true old growth which means it has a tighter grain pattern and is far denser than anything available today. Given that density and hardness, your best bet is to take very light passes with the jointer. It will take a lot longer, but the results will be worth the effort.
The tools don't make the craftsman......a true statement often overused by individuals who haven't a clue about quality tools or true craftsmanship.