what thickness should i use? the motor is a stock d16a6 i have found 0.000" standard size, 0.50mm undersize, and .025mm undersize

 

What ever thickness that your measurements have told you to get. Is this a serious question? I hope you understand that while "slapping" an engine together may work for some (and the few it works for they are so proud of it they brag about it everywhere they can) It's nowhere near an intelligent idea. For every one person that has success there is 100+ that have failures with this method.

The proper way would be to have a micrometer gauge and measure everything to find your true bearing clearances. Plastigauge is another "tool" you can use but isn't near as accurate. Your eyeball, gut feeling, or guesstimate is laughable at best. Unless you like assembling engines only to tear then back apart after you start them up to tear them back apart again? Then slap whatever you want in there.

 

Also be aware that "standard" ACL race bearings are generally thinner than others.

I'd get a standard set and plastigauge it to make sure your clearances are correct

 

Take the crank to the machine shop and have them mic the journals. Then they will inform you what size bearings you will need.