I don't like the flying sawdust from a Makita mortiser. Somehow always ends up in my eye, and all over my clothes, in my pockets etc. I also get annoyed with cords run all over, especially when I want to sweep(if in shop). I like the old boring machines(though I have not tried to work at a production rate, only at my pace/leisure). Dry white oak is harder to bore than green white pine, but as has been said, you can make up for that with a correct gear ratio on your boring machine, and a sharp bit makes a big difference. The charactersitics of drilling/boring, and sawing and parring, don't all get harder or easier in a given type of wood. Sawing in a dry hardwood may be easier than green, while the parring may be harder(like on a tenon). They are different types of cutting. There aren't any that can't be worked. If your client want's reclaimed dry oak, you can give them that, it may be a little bit more work, but so? If you are trying to provide quantity, sure green white pine is probably easiest. I'm going to build my own frame from dry hardwood timbers. For me, the finished product from these old growth timbers will be worth it. I'm also going to spend extra time on the finsh.
I would suggest that you not be daunted by the material you choose, it's all workable. Unless you're very out of shape, I would also recommend you get a boring machine to try(Jim Rogers can hook you up with a good one). We tend to prefer Millers Falls or Boss machines. I started out with a snell. It's useable, but do prefer the aforementioned as they are a little bit more rigid. You can always sell it later if you want to. They don't tend to lose value as much as a power tool. Keep is oiled and make sure you don't have too much slop in the gears or bearings... they've lasted 100+ years already...