It really depends on your budget, but...

Je 8.8:1 (If you're going turbo, 10.5:1 or 12:1 if you're staying N/A)
JE rings or totalseal rings (depending on your final power goals.)
Eagle rods are fine as long as you're not planning on making 400+ hp.
Clevite or ACL bearings all around
ARP Main and Headstuds; Exhaust mani studs wouldn't hurt, but you can save money buy buying factory replacements for the 4g63t (They'll work just fine; I use them for my turbo mani.)
OEM or Cometic MLS headgasket
Mechanical timing tensior conversion (Not necessary, but it is nice when re-timing the motor; Plus belt tension will be more consistent throughout the RPM band)
Melling High-Volume oil pump (If going turbo)

ModernPerformance has about the best web pricing I've found on a bottom end kit for the 420a Around 1k. Howell Automotive has a great selection, but also has a reputation for poor service and very lengthy waiting times.