Adding my vote for the DS - yes, the viewfinder is a big deal, especially since you are talking about using lenses with F4 as max aperture. I used to own a DS, now I own the K100D because my DS was stolen. The DS viewfinder is better than the K100D or K200D.
The DL and DS have depreciated so much that there is hardly any price difference between them; you're getting a huge deal on that viewfinder especially since it is now only used in the semi-pro level cameras.
The DS is a great choice and I love the pictures I took with it when I had it. Shake Reduction is a special purpose feature, some need it a lot, some don't need it very much. Go for it now so you can get back to shooting!
A word about decision making. The longer I'm in the hobby the more certain I am that I can never be certain what equipment I want
I also think you are right to prioritize lenses in your budget at this level. Whatever gives you the most creative freedom.