You're going to get the carboy sooner or later, so this may just be the excuse you're looking for! But, if not - you'll be fine with a single yeast pack w/6gal in a bucket. The biggest problem is that you're bucket will be tied up for months while it ages.
Atomic Dog Brewery
On Deck: Centennial IPA, Dry Irish Stout
P: Cascade Pale Ale
T: Carbed Crystal Light, Root Beer, Vanilla Cream Soda, Tripel IPA, Apfelwein
e^(pi*i) + 1 = 0