Ive been brewing kits for about a year now and have really enjoyed the process of making them and mainly drinking them

After reading lots of posts from past kit brewers, I think it time to move to AG brewing

Im looking at buying the Hope and Grape AG kit ( http://www.hopandgrape.co.uk/catalog/de ... HA20225648 to get me started, but ive a few questions before I buy.
Am I best buying the AG kit with or without a thermostat?
What benefit does the twin element version give me?
I have all the general equipment for brewing kits. Do I need anything else other than the H&G AG Kit?
Once I have all the equipment do I only then need the ingredients for the recipes?
Sorry if these questions have been answered many times before!
Thanks in advance,
neggs.