A Weatherby with too low a comb!!?? Thats a new one. But if the rifle has a stock that is designed for use with iron sights, chances are it will not provide as good a cheek weld if you mount a scope on that rifle. Conversely, the McMillan Stock on my Brno 602 would knock my teeth loose when I shot the rifle with irons because I had to have my cheek mashed down so hard on the comb to see through the ghost ring.
Not all scopes, mounts, or rifles can be used interchangeably. If your scope has a large objective lens, it must be mounted higher to clear the barrel than a straight tube scope. If your rifle has a heavy barrel contour, the scope will have to be mounted higher to clear it. The higher that the scope is mounted on your rifle, the higher the comb needs to be if you are to acquire a good cheek weld. If the ocular bell of the scope lines up with the bolt handle, it is more likely to cause clearance issues than if the tube does. Some variable power scopes have very long eye pieces making them more difficult to adjust for eye relief, particularly if the long eye piece is fitted to a scope with a short tube length.
Determine first which rifle you want. Next determine which scope is the most practical for your application. Now determine which mount provides the strongest mounting solution for that scope on that rifle. It should position the scope so that you can acquire a good repeatable cheek weld without having to go on a quest to find a full sight picture. If the scope is a variable, at the low power setting there should be enough eye relief that you won't get hit with the scope. At high power you shouldn't have to crawl the stock to attain a full sight picture. If you have a full sight picture the instant your cheek hits the comb, and if you can cycle the action while the rifle is at your shoulder, you've got it right.