And I didn't realize it until I got home but I got the rifled barrel version.

Considering that I bought it primarily for 3 gun and possible HD duty on the side this isn't going to work. I'm going to call the dealer and ask if they'll let me swap barrels if they have a smooth bore in stock. If they don't I'm gonna have to buy one. So do I get another 22" w rifle sights and cantilever rail or go with a 24" VR and have a rear sight milled in later if need be? Both are about the same price.

You're probably not going to be surprised by this answer... I got both.

My SLP Mk1 came with the 22" barrel.  The sight picture with the cantilever rail seemed too cluttered for me, so I ordered the 24" VR barrel.  I feel faster with a VR barrel.

YMMV,
-Randy

I called them up and since I didn't fire it they let me switch out the whole gun.

I put a few slugs and some birdshot through it today. Man I like this gun!!!! Now for some mods, bolt handle, weld the lifter, bolt release etc

That is one fine gun store you have there.  NO store that I know of would swap it out regardless of it being fired since it is pre-owned and registered.  That is outstanding service.  If I were you, I would drop off a six pack of beer as a thank you.  They saved you over a hundred bucks for a new barrel.  

registered with who?