A 4x5 Graphic should be about the same price as a 2x3. 4x5 would be a much more flexible option. It would have a longer bellows, a wider range of movements, a larger focusing glass, and, with its international back, would accommodate film sizes 6x6cm, 6x7cm, 6x9cm roll film (with roll film back), 4x5inch sheet film as well as Polaroid.
Another question is why a Speed Graphic instead of a Crown Graphic? To me the extra weight and bulk of the Speed Graphic's focal plane shutter isn't worth whatever possible gain one might get from the second shutter.
I love using my Crown Graphic with 90mm Super Angulon, 150mm G-Claron, 210mm Sironar lenses, 6x7, 6x9 roll film backs and, of course, 4x5 sheet film. (These things I have accumulated, used, over time. At $350, only the 210mm Sironar was expensive.) I removed the rangefinder so that I could make the camera and all the lenses and accessories fit in a small backpack. A very nice detail is that the 150mm G-Claron is small enough to remain on the folded camera. This makes for very quick set up. The outfit is so convenient that, despite having also a metal field camera and a monorail view camera, I use the Graphic most often.