Amarinf:
Dear Joy,25965 is great.. but study your current consumption.
Do you really require this IC ? Also a good PCB design is must for this IC.
On other hand, 317 is easy to use and no special PCB layout needed ...if your current requirement is not going beyond 1.5A
Using a linear regulator for 1.5A with a 25V voltage drop is sheer madness, that's 37 watts
of wasted power to dissipate as heat, a DC-DC converter will be 85% efficient or so.
Use a switching converter, not a linear regulator.