I don't know where you are, but I have a rideable "Fit Stem" http://tinyurl.com/2e7uxvc I would let you borrow. You would need to leave a deposit (fully refundable upon return). There are a lot of workarounds on bike fit... i.e. stem length, stem rise/fall, seatpost length, seatpost setback, different handlebars can drastically change your ride position, where you are positioned on the seat rails, HT extension risers, etc etc. If you are determined to stick with this frame and you are not utterly, drastically off base for size, you should be able to get something to work. In my experience, hand problems nearly always come from a too-high seatpost and too-low handlebar position. We're programmed to see the arrangement as attractive and correct due to bicycling's love affair with racing. Unfortunately, that is not how most of us ride and need our bike to fit. When you are racing, your legs are working along with your core to hold your body up by the strong downward force of your stroke. Your hands are very loose on the bars. When you're just pedaling through town, that force is not there, and you are left leaning on your palms, which is painful.
Also of note if the reach is too long, you might try some of the "randonneur" style drop bar designs. The tops flare back to allow you a more upright position when using them. Nitto makes a nice one as well as Modolo (through Velo Orange). I am set up to do personal fitting and have a number of bars you could look at to get an idea. If you want to look it over and even use the rideable fit-stem with your current set-up, that would be fine. No charge. I wouldn't want to lend out any bars without a fee, though. I'm in the western 'burbs.
Remember too, as you raise the steerer height (with an extension) you bring the bars closer to you.
I was looking back over the numbers you provided above. Seatposts are reasonably common in very long lengths---driven a lot by mountain bike designs as well as the more recent popularity of compact road geometries such as yours. I would not be surprised if you could get an appropriately sized post, which would be about 65mm longer. 40 centimeters (~16") reach is another thing... are you sure that's right?! That is an extraordinary amount.
*Do you already feel stretched when on the tops? That is, not on the brake hoods or in the drops, but on the flat section nearer the stem clamp.
*What is the reach of your handlebars? http://www.sheldonbrown.com/gloss_ra-e.html#reach Definition 2. Handlebar reach can easily vary by 40mm or more.
Remember too, as you raise the steerer height (with an extension) you bring the bars closer to you. Also remember that as you raise the saddle, the bars get farther from you. It is a bit of a balancing act.
As for your shoulder position, I think I would have to see it in person. Is that something you hadn't noticed before it was mentioned to you?
BTW, Wig is totally right. It is a bit of a theoretical exercise without being able to see your relation to the actual bike configuration.