bridge type

so im buying a cheap guitar, and making worth a mint :D firs things first - to increase the sustain... what material is best for the bridge? and is through body stringing best? please note im not asking what make of bridge is best! but what materials are better? what do you guys think?

Hi guys this my first post been browsing a wild. I have been playing on and off for years (more off then on) and I just started playing again. Id like to get more into it so I have a few questions.. I have a B.C. Rich platinum series warlock number 21130854. Im not sure what the bridge style is...