Rod/Main Bearings?

[BlazedGlory]

I have an S13 SR20DET, and plan on doing a slight build before I slap a bigger turbo on, cams, valve springs/retainers, possibly pistons/rods (not sure yet), main/head studs, etc.

I've read it is a good idea to do bearings as well. In searching I read there are different sizes and whatnot? Should they be measured to check engine wear or something before you buy new ones? I found these on ebay - they are available in standard, .25, .50, and .75mm oversized - would I just get standard? I'm just trying to get all the parts together that I can before I even begin to start actually upgrading the engine...

http://cgi.ebay.com/JDM-NISSAN-SR20D...QQcmdZViewItem
http://cgi.ebay.com/JDM-NISSAN-SR20D...QQcmdZViewItem

thanks!