Definitely hit up the vendors. Swaybars are the best bang for the buck for the whole car, hands down.
I love to support vendors, but I would get swaybars installed before dropping $1k on coilovers. It's 50/50. 50% chance that the swaybars will be enough and you'll be happy as a clam. 50% you'll be hooked and want an even flatter ride with more grip. When that second 50% hits, start hitting up the Flatout guys. But with supension I'm a strong advocate of slow-and-steady buildup.