Which day are you going?
Plenty of people were willing to help me out, and while I'm far from an expert, I'll offer to help however I can if you're there on Saturday. I can't go on Friday.
As for taking plastic, I've only commissioned one rifle, and the builder I worked with did not take plastic. That's probably for my own good, lol. I would think that's on a case by case basis, however, and I can't speak to what others do or don't do.
What you will find is that pretty much everyone is friendly and will talk to you about what you're after and help you learn how to decide what it is you're after. You'll get to see a lot of guns. Some makers don't want you to handle their displayed guns, so be sure to ask first, but MANY of them want you to check out their displayed stuff, so you WILL get to handle rifles and see what lights you up and what turns you off. And there will be folks there who do hunting bags, powder horns, molds, leather work, knives, artwork, etc.
It's a heck of a good time.
If the planets align and I can get Matt/PA and Retired_Rusty and I there with you, you might be best off leaving the plastic at home. Trust me.