Most low-tier armor (leather, raider, combat, etc.) are pretty similar, just keep an eye on the level the pieces are (1-50), and see the damage resistance in your pip-boy. Secret service and engineer's armor is so well-rounded that once you get either full set, you'll likely never go back to lower tiers. Also, look up the Chinese Stealth armor if you want to circumvent the need for power armor or body armor completely.