Looking for bearings for my '82 Gran Fury LA318 - mild performance engine, daily driver driven severely.

How do I choose the right main/rod bearings? I see so many options: Bi-metal, Tri-metal, 1/2, 3/4, full groove

Which type do I choose? I intend to drive this car hard on the street for many years before I have to rebuild it...

King SI bearings any good? Looking at the bimetal 1/2 groove version

Look at clevite they are good. Seems to me you are going overkill for a 318 that will be a daily driver. You aren't going to be able to drive it hard enough on the street to worry about using high dollar race parts. Not trying to burst your bubble but with the weight of the car and the engine and drivetrain combo you are contemplating I believe you are going to be very disapointed in the performance.

King is top-of-the-line IMO. But overkill for your use.
In terms or what you plan any stock type bearing is fine. A name brand tri-metal will give long life and performance and not break the bank.
I don't use full groove mains. If it's racey I'll go 3/4 groove but most builds get std grooves. The longer the groove, the longer (in terms of crankshaft degrees) the oil bearing is exposed to pressurized oil. Full grooves reduce the load carrying ability of the main bearing but when coupled with a higher volume oil pump it lets the rods take more abuse.

Reasonable power in a stockish build just us the stock type "P" bearings. The embedment characteristic is desirable, nothing to be gained by a "H" type for what you're doing