Find out what the TT of the road bike and see how it compares to the cross TT. The rule of thumb is to get a frame that's a little shorter in the TT. The Giant that I race comes in about 0.4 cm shorter and it works fine. Also, remember that the standover height of a std cross bike will be a little taller than a road bike since the bottom bracket drop is less for a cross bike. As for the cranks, I would go with the one with the smaller rings but it depends on your fitness. As for the derailleurs and shifters, go with the cheaper ones since cross is pretty hard on 'em...you can always replace 'em.
On my stuff, I went old school, meaning that I use bar ends for shifting and std brake levers so if I biff it and bent a lever, the shifters wouldn't be affected.
There's a old saying that someone told me, "if you ain't crashin', you ain't going hard enough!"