If you're on a real limited budget, harbor freight sells a "5 in 1" iron that is 30 watts. If you use the largest brass tip and tin it well, it will solder 8 guage.. just barely. Don't get one of their guns though.. they are junk.

If money isn't the top priority, I would go with one of these stations listed in this order: Hakko FX888d, trakpower tk950 analog, weller wes-51