You'd probably be using some mix of better turbofan/turbojet engines along with ramjets/scramjets and 50-60 years of materials sciences advances. So, yes.
Don't underestimate the J-58. This is as much if an extraordinary engineering feat as the SR itself.
I respect the J58's place in history, but it has no place in modern aviation. The ideas behind it still remain relevant, but the implementation is long, long outdated. I think it could be redesigned and reimplemented for cheaper that it would cost to resurrect and maintain the original J58.