new bearing are always a good idea when the engines out as for brand im not sure with 3.8L but in my mustang i used clevite bearings and you never wanna cheap out when it comes to rebuilding motor and its always a good thing to know that all that stuff is brand new heres a few links to think about
Clevite Engine Parts MS2037P-25MM - Clevite Main Bearings - Overview - SummitRacing.com
Clevite Engine Parts CB1238P026MM - Clevite Rod Bearings - Overview - SummitRacing.com
and dont forget a good set of piston rings
