Your ideas of a long range hunting bullet sound very interesting. Of course, the proof is in the pudding. I think Shawn outlined the requirements very well. I'll take a stab at summing up my thoughts on it.
1) High BC, high velocity and accuracy are paramount. You know this already.
2) Good, reliable terminal performance. If your shot placement is perfect and the bullet either lasers through or fails to penetrate, it can make for a very bad experience. For a one bullet at all ranges solution it would have to expand and provide adequate damage and penetration at short range as well as long. A one bullet solution is much, much more preferable to developing loads and carrying two cartridges for for short and long ranges. IMO, for a bullet to be reliable it would need structural integrity as well as certainty of expansion. I believe exit hole are very important, because they provide both penetration and, if necessary, a blood trial. The more mass a bullet retains, the farther it will penetrate. The more penetration the more damage. Some shedding of shrapnel and the resulting collateral damage may desirable. Good reliable performance will produce results with less than optimal shot choices.
4) Low expansion velocities. IMO, to make what I call an "ethical" shot, one should be confident that the bullet will open and expand at the range it is fired to. Many bullets advertise about 1800 fps as their minimum performance velocity. If that velocity could be reduced to 1600 fps or lower it would increase minmum opening performance range.
3) Twist rates and stability have already been mentioned. I'm sure you realize one of the challanges of making high BC bullets is stabalizing them. As mentioned, they usually require greater than normal twist rates for calibers. My guess is, that there would be a relatively small market for LR shooters looking for high BC bullets requiring custom barels with tight twists. There are a few here on this site, but most LR shooting is BR competiton type shooting paper. You might consider two or more offering in a particular caliber to include standard twist rates.
So far, the closest thing I have seen to a perfect hunting bullet is the GS HV...
GS CUSTOM BULLETS - HV Bullets
They are a monometal bullet with driving bands similar to what you describe. Unfortunately, they dont have many high BC bullets in the HV style. They do have some in the SP style....
GS CUSTOM BULLETS - SP LONG RANGE BULLETS
Here are the advantages of the GS bullets as I see them.
Their design results in higher velocities over other bullets of similar weight in the same caliber.
They exhibit outstanding terminal performance.
They are reported to be very accurate.
They are reported to be very uniform and precise.
They have a moly coating that facilitates both velocity and barrel life. Greater barrel life is a big bonus for overbore cartridge shooters. And their moly supposidly is easily cleaned and does not moly foul the bore and reduces copper fouling.
Their biggest draw back is that so far, they have few high BC offerings in the HV hunting bullet. However their 177 HV in 30 cal has an advertized BC of .638. I'm a little skeptical of that, but if it's cloce to that for that weight bullet, combined with the increased velocity potential of the bullet, it far out shines anything else off of the shelf for LR hunting in the 30 cal.
If you read through their site, you will find a lot of very interesting information on external and terminal ballistics. They know a lot about it.