The GS 45 is in my opinion at the top of the list you presented. Built like a tank, fast, well thought out, and most importantly, a truly great sailing machine.
Your list should also include the Dufour 44 Tall
rig and deep keel. It is more expensive than the other selections by about 50K (new) but well worth it.
The Dufour 40 comes in under 300K (new) with everything on it. X Yachts builds a very fine machine as well with a high quality construction and very positive agressive hull design. X- Yachts are know for their oustanding performance and the company proudly stands on that reputation. GS is every bit the boat and thensome.
Dehler is a nice boat that offers a lot of "class" in its interior concept. Excellent engineering is incorporated into every aspect of this boats design and build from the keel up. They are also reputable boats. Dehler factory seems to have pretty much passed on the USA market where GS has a USA base and support as does Dufour and X Yachts. There is a dealer acting as the importer in Chicago but I don't know how active they are. You don't see them in the major shows anymore.
Let us know where you are in the selection process.
Best of luck!