There are two main parameters for CAP. First is ESR (equivalent serial resistance at defined frequency - lower is better), the secon is ripple current (higher is better, generally ripple current increase with capacity).
If its possible to choose 105°C or 125°C design, choose them. The life time will be longer at the same condition than 85°C.
I used for DC/DC convertors Nippon LXZ/LYZ series capacitor in case of trough hole. In case of SMD capacitors seems to be polymer CAP (eg. Sanyo/panasonic/nichicon) good solution. Polymer caps are currently used for e.g. matherboards DC/DC convertors. There is lower capacity, but much higher ripple current.
In many cases I used trough hole cap from nippon instead of SMD - you can solder wires on PCB pad and fix cap eg by thermo-glue. It depends on package and requested value (higher nominal CAP voltage you use and the CAP life time increase)