Hey, i'm not really here for competing against others; just wanna sit back and go through a story without much grinding etc?
Any suggestions as to what republic class I should play
Least grind? Go with a stealth class, which means either a shadow or scoundrel.
Scoundrel healers are pretty good, if that appeals to you. Shadows also get their healer pet fairly early, and since you can spec for tank, they can be very durable.