At level 80 my toons still have the gear they start with. From 80 on I start gearing them up with quest rewards. Heirlooms are nice but unless every party member has the same you will be throttled on the toons that have less, assuming you do RaF.

You need to pick a class thats fun to you. If you pick based on what heirlooms you have, you may end up starting over if you find you dont like melee, or boomkins, or whatever.

Raise 3 druids to 20 boxing, 3 palis to 20, etc, then pick your favorite?