RE the "playing 6 string stuff on 7", although to me it never feels right, especially for metal (where the bottom string truly is home!), the guys in Obscura I've only ever seen use 7 strings despite having many songs never touching the 7th, and they sound rather fantastic. Now, to me, and maybe it's a string gauge discrepency, playing it that way never sounds right, I can't attack the string in the same manner... but if those guys can make it sound like that, then I'm sure it's possible.
No matter what, I'll always feel most comfortable on 6 string guitars, I have played 7s for possibly an equal amount of time but I still can't feel as natural as I do on a regular guitar. For that reason I'd really stress the importance of trying a 7 string first, before dropping the Mayo-money on a high-end one. Some people, as you'll find in other posts, are far more adaptable than myself and find the extra range just gives them more freedom, which is also undeniably true. You'll just have to try it yourself!
No matter what, I'll always feel most comfortable on 6 string guitars, I have played 7s for possibly an equal amount of time but I still can't feel as natural as I do on a regular guitar. For that reason I'd really stress the importance of trying a 7 string first, before dropping the Mayo-money on a high-end one. Some people, as you'll find in other posts, are far more adaptable than myself and find the extra range just gives them more freedom, which is also undeniably true. You'll just have to try it yourself!