I'm not an expert by any means but I believe these are correct answers, I could be mistaken though.
The longer the forward grip the longer site radius you will get.
As far as configuration goes that's more of a personal preference. What will you use it for, a varmint rifle, CQB, etc? I would definitely at a minimum get a chrome lined barrel. The other things you can do as you get a feel for the rifle.
Once you decide what you want... or before is probably the best bet, you will probably have to set yourself up as a registered user in order to access the cart, and place an order. Have you got an FFL arranged yet? You will likely need that info as well.
The longer the forward grip the longer site radius you will get.
As far as configuration goes that's more of a personal preference. What will you use it for, a varmint rifle, CQB, etc? I would definitely at a minimum get a chrome lined barrel. The other things you can do as you get a feel for the rifle.
Once you decide what you want... or before is probably the best bet, you will probably have to set yourself up as a registered user in order to access the cart, and place an order. Have you got an FFL arranged yet? You will likely need that info as well.