I would recommend Sherwin williams Ultra 7000 clear coat. I`ve been using this for 7 years now and I wouldn`t use anything else. Its very user friendly, holds a nice shiny gloss, and has the flex additive built into the clear where as other companys make the flex a separate additive to buy.
1 quart CC930 clear coat- $54
1 pint UH904 hardener-$41
1 quart US-1 reducer-$14

1 3M respirator-$25

I know this seems expensive but it will be worth it, and that 1 quart of clear you could probably clearcoat 300-400 faceplates. So its pretty much and investment that will last a long time and give you the best finish and protection to all of your hard work. AND THE RESPIRATOR IS A MUST!!!!!