On my Rem 5R in .308 I have a Badger 20 moa rail and Leupold Mk 4 steel rings and I'm very happy with this set up.
Something to consider is height as all manf do not make rings to any sort of standard height.
I note that you don't tell us the objective size of your scope. In steel, the lowest rings I could find were Leupold MK 4 which came in at .84". NOTE: Leupold doesn't make "low" rings...they make "medium" and up and the "mediums" are lower than any other I have found in steel. And, these Leupold rings came highly recommended and I have found no reason to disagree. They are rock solid.
Mark 4® bases and rings are strong, lightweight, and exceptionally durable. Available for virtually every long-range tactical rifle, we have the Mark 4 mounting system you’re looking for.
www.leupold.com
Now, this is for a Vortex Viper 3-15 x 44mm scope and this gun is primarily a hunting rifle with 20" barrel but it shoots well enough to also be fun at the range. If I had a bigger objective, I would have to have gone up in height.
If going aluminum, consider the American Rifle Company M-10 rings. I have them on a 6.5 CM target gun and really like them....particularly that they are fairly low profile on top and mostly because when you tighten them, the scope doesn't rotate and fuck up your level (and yes, for no really good reason I'm anal about level).
www.americanrifle.com
Hope this is somewhat helpful.