Weber has a 10% off sale this weekend and that would put their 8CM100 kit at about $500. Does anyone have any experience with this kit? I notice that it comes with a couple of variations. You have the choice of four EL34 tubes or two KT88 tubes. What are the pros and cons of the two different configurations and tube types? There is also an option for different OT, one with high headroom and one with low headroom. I'm leaning towards getting one with EL34's and the low headroom OT. Any thoughts?