I don't know about pre-bis but I have lot's of easy to get gear on my shammy. You will need rank 8 for the legs + gloves, den watcher shoulders OR rank 10 if u can. Hat get Crimson Felt Hat its nice and easy, 30 spell power gg. Frostwolf cloth belt is great, double advisors rings, or the long thrall quest chain ring is nice too. Briarwood reed is good trinket, other trink you should have the horde insignia. Frostwolf Advisors cloak for back, Barbed thorn necklace for neck, and for chest you should get Zandalar Augurs hauberk, just get one from a raid and buy revered for like 300g its easy. Now the hardest part is the weapon. You can get that shitty 1h mace with 14 spell power but its slow attack speed. You need high attack speed to help keep locks mages and priests from casting. I would recommend hand of edward the odd, or just get any fast dagger regardless, until you can get a 20+ Spell power dagger from MC or ZG. Long term goals are mind fang though. For boots, I dont know I just use the rank 7 ones for now. Try to get heart of hakkar too.
Good thing about 30/0/21 build:
http://db.vanillagaming.org/?talent#hE0zAcMqZZVfcb0xoYou start off with fuckn 11% spell crit and basically you own. I can kill people naked with shield and weap lol.