Are these good? They look fantastic. How’s it compare to the WBP?

http://www.atlanticfirearms.com/component/virtuemart/shipping-rifles/polish-ak47-circle-11-rifle-fs-detail.html?Itemid=0

Don't know, but I like the looks of the underfolder model.

http://www.atlanticfirearms.com/component/virtuemart/shipping-rifles/polish-ak47-circle-11-rifle-uf-detail.html?Itemid=0

I can't say, but I did take a hard look at it before landing on the WBP instead.  I'll pick up the WBP from jail in 10 days (just arrived at my FFL today) and let you know my thoughts on that rifle...  Let us know if you decide on the Circle 11 and how it works out for you.

It's expensive, but that's how it goes. I don't understand why it would need to comply with 922r if these were built by Atlantic.

The only reservation I have about these guns is that I fear that the barrel and receiver are commercial grade, even if they are imported.

In the end, it doesn't really matter to me, because I can't afford a thousand dollar AK. I just follow these things in case I find one on the used market so I know what it is worth.

I was thinking that but didn't want to say it out loud.  I am not paying $1000 for an AK (again).  This Arsenal SLR-104FR is my only $1000 AK.  It's not worth that much more than a WASR or another of the cheaper AKs to me.

Totally get that sentiment.  I have to admit that when I grabbed the other Polish variant from Atlantic, I had sticker shock.  It was an impulsive "damn, that's sexy" moment.  But, my NPAP was getting lonely, so now it has a friend in the safe (or, it will in 10 days after it gets out of jail).  

Realistically though, the days of $500 AK's are kinda gone aren't they?  The mighty WASR is $650 these days, NPAPs are $550, and these are the go-to entry level models for a lot of folks.  I wish I'd caught the AK bug sooner so my hobby would be cheaper!

These are rifle built from parts kits from military rifles.
The date on the one linked in the OP is from 1970.
The Poles switched to the PMKMS underfolder around 1973.

The trunnions, bolt carrier, and bolt will be machined from forgings, and they would most likely be using the original barrel pins.
They are quality parts kits.

How well Atlantic Firearms built them, I can't comment on.
They certainly look very nice, and the Radom hammer forged barrels are supposed to be very nice.

The Childers receiver is going to be the closet thing to what the rifle had originally, as they are made from Polish 80% blanks.
The quality of the receivers is outstanding.

$635 for the "Paratrooper" - https://www.atlanticfirearms.com/component/virtuemart/shipping-rifles/romarm-paratrooper-ak47-detail.html?Itemid=0

That's 42% less in price.  I don't think there is 42% more form or function in the Circle 11 (my opinion).  I totally understand why people would buy them, however.  It's a beautiful rifle, and AKs aren't cheap these days.

What are the differences of these two?
The marking on receiver and furniture?

Top one has Boyd's red furniture and Morrissey receiver

Bottom one has polish laminate and Childers receiver

Otherwise no difference