[niterydr]

Are you going to be doing the assembly?
I would recommend King or ACL bearings (I've been using them for 2+ years without problems).
A turned down balance shaft is a good option, it gives you the rear bearing support.
ARP Mains are nice, but the stockers hold plenty of power. Since I have seen stock motors that aren't "perfect" we have all of our blocks inspected and most of them atleast honed. You get what you pay for when it comes to engines and machine work. I would highly recommend having the block machined with a torque plate.

Any stainless steel valve will be happier in a brass valve guide. We have had excellent success with SI products.
If you need help fell free to send myself or John a pm. Combined I think we have the most 4g63/mitsubishi high performance engine experience (motor assembly, machining, parts research and development) in the twin cities. (Minus a few machine shops that have been used by multiple shops. The assembly techniques are not the same, but they do know what "we" like to see for machining tolerances).