Hey guys I have a Howa 1500 .223 and have just purchased the bushnell AR223 4.5-18x40 scope.

Which would be the best way to mount it ?
Mount it with rings directly to the receiver or to a picatinny rail ?
Also does anyone know if I need medium or high mounts ?
Does anyone else have this sort of setup ?
What are you opinions on the scope ?

Thanks