Right now the best option I have is a Classic with OD green furniture for a little over $1k (black is on backorder, but I like the idea of the OD). A few questions...

Handguards-
Is the standard handguard the "Swiss" style that is compatible with their add on rail kit?
Was the "fishgill" handguard ever offered in OD green?
All I want is a rail for a bi-pod. Any good third-party options?

Optics-
I'm interested in something in the 3-6x range, no batteries, preferably under $200. What are the best options considering the charging handle issue?

Ammo-
What's the cheapest way to feed it (not including reloads)?
I saw a Herter's box at Cabela's labeled ".223(5.56NATO)." That concerned me...

The dimensions of the cartridge are the same. it's the chamber of the rifle that can be different. The Sig 556 has a 5.56mm chamber. No worries there.

The dimensions of the cartridge are the same. it's the chamber of the rifle that can be different. The Sig 556 has a 5.56mm chamber. No worries there.

I decided to make it official and order the OD green Classic when the guy behind the counter informed me that the rifle did not include any form of rear sight. Apparently, the diopter costs $200.

So there's 2 questions.
Will a milspec flip-up rear sight from a M4 work, or is it too tall?
Any reccomended optics?

Get a Samson front sight then you can run any AR type rear buis. Both should cost less than just the Sig rear. And work better. I have one and a larue fixed rear buis.

Get the Aurora sights

I ordered a MI front flip sight..

I have an extra M4 rear sight that should work just fine. Now I just need to pick an optic and find a front rail for a bipod.

I'm thinking I may need some kind of cheek riser, though.