I saw this posted in other forums here, but though it would be better here.  

I have a similar situation with ultimately the same question.   Any recommendations?

The "best" would of course be the Burris rings w/ the inserts to let you adjust/add/remove MOA in any direction so you can be closer to mechanical zero.

Other than that, whatever Weaver rings, etc. you want really, blue vs black vs silver is a fashion choice only you can decide on (I'd rather have better rings w/ mis-matched finish than something that looks good).  With the 50mm objective, you will need extra-tall rings.

If you don't go with the Burris rings, consider adding a 10 (or more) MOA mount if you intend to shoot out to 100 yards and beyond (bowling pins and silhouette rams at 200 yards are fun with rimfire - almost like artillery)

On my 10/22 "T" model I have medium rings with a 6x18 50 scope and it's about the perfect height
pic here
http://www.wtv-zone.com/SgtRock/The10-22s.jpg

With that much magnification, you will need the Burris Signature Zee Weaver-Style Rings mentioned above and at least a 20 MOA rail.   I have the EGW 20 MOA.   I think you can get the rail in silver, but I think the Burris rings are only in Black.   The higher the magnification the less vertical MOA adjustment you have in a scope.

Ditch the Ruger base and install an extended Picatinny base.  Pick whatever height rings or QD mount you need after that.

I have an RDS mounted on the front of this rail, but don't have any pictures.

Burris Signature Zee 1" Rings - you might be able to squeak by with Medium (#420522 in Nickel) with 0.77" height to centerline but likely you'll want High (#420532 in Nickel) with 0.92" height to centerline especially if you're putting lens caps on it.  Should be able to find a set for $30-40.  I've got one with a Nikon 40mm objective mounted in Medium rings so going to 50mm is almost certainly going to need High.

Wow.   This is good input.   Thank you.