Wow Matt, your tank looks awesome; definitely some food for thought there. I'm glad you pointed out the limitations of a small opening when it comes to aquascaping - I'm sure i'd have completely forgotten when it comes to choosing my rocks! I see what you mean in the corners now - you basically make it look like there are no corners, so the eye thinks it's looking at a section of a larger 'scape...And with the sloping front to back, are you talking say 3 inches at the front, to 6 inches at the back, or more extreme than that?
I'm still confused over what filter to get. There seems to be some debate over flow rates. I estimated 400-500 L/hr but I see lots of similar sized tanks with Eheim 2215's or even 2217's.
I guess, if I go 600 l/hr that's going to be about right? I was thinking about the Tetratec EX 600, which I can get from Germany for a really good price, with free delivery. There are sometimes benefits to being in the EU!