Coming in late on this, but if you'll look at it historically, you will find that for the most part high or straight stocks were predominately used for flyers or what became trap shooting, i.e. target games that allowed a pre-mounted gun. Skeet as a target game came along much later & was not a pre-mounted gun game at all, that came later when folks wished to play it as a game in and of itself and not use it as originally intended, as a method for improving one's field skills.
Jay's comments are particularly poigent, in that the lower stocks [more drop] are much easier to shoot for targets that are shot after they have come into view [the field] and particularly so when they are approaching. I would go so far as to say that the reason that most classic English game guns had the drop they did was because it is much easier to shoot a driven or overhead target [think vertical or very nearly so, please] with some drop in the stock than not. High overhead targets are quite challenging and they are for the most part absent from today's Sporting Clays events, even with the use of a tower .. and too, today's 'shooters' will whine about some kinds of presentations and much prefer to pre-mount thier guns, even if the rules say 'any mount' [wink, wink]. To answer your question, SS, I'd say go buy your older classic American gun of choice and don't worry about the drop at all. Should you end up selecting one that does have some drop, then when next in the dove field simply move out into the field a short and polite distance and face the trees the birds will be flying in over. Wait until they are just over the field's edge and THEN raise that impossibly bent gun to your shoulder and put the bird in your bag. I expect that you will find that you can do exactly that .. and also that you cannot with a straight & high stocked gun, or aleast not near as easily. What I am trying to convey is that the older classic amounts of drop were not arrived at by accident. Rather, they were quite purpose built, for taking driven/overhead targets, primarily. Passenger pigeons were the target of choice for many here when we had them and before the mast was all felled that they needed for nesting. Having one's face tight to the comb and parallel combs is a more modern form .. and one primarily for target shooting.
FWIW, some of the best shots in the field and on the ranges, people like Albert Topham on a skeet field or behind a dog or Cyril Adams in the ring NEVER premount when calling for the target. Both use some drop and both are wonderful accomplished shots of record.
We also have a very gifted and generous member on this board, Mike Orlen, who does stock bending among many other skills. I suggest you contact him once you've found and acquired your American classic should you decide that it must higher &/or straighter.
Such topics are always interesting and they make for lively discussion, but for the most part our forebearers had it figured out quite correctly for their intended use .. a well fit gun takes the bbls to where the eye is focused, and for very fast directly overhead targets that is easier with some drop.
