Kong,
Take a look at this site
http://www.bardenbearings.com
They are the go to guys for spindle bearings. They have a spindle repair video and get a copy of the machine tool bearing catalog.
It will have lot's of info in it.
I would suggest you use a duplex pair of angular contact brgs on the tool end and a single or double deep groove radial on the pulley end.
I would use Phenolic cages, and shielded brearing. Expecially on the tool end to keep the chips out.
Class C- 7 or C- 7P are the best but cost lots more.
Also the amount of lube makes a difference, if there is to much it can generate heat. To little and you can tear up the bearing.
Hope this helps and good luck. Nothing ventured nothing gained.