I'm a little confused about what you're asking. Can you be more descriptive?
You say you want a "rollover", yet that term normally applies to incorporating a so-called roll-over cheekpiece into a stock when it's first made.
You said your stock is currently "too hard on you", so I assume you mean recoil punishment to the face. Since you seemed to consider an adjustable comb (but nixed that idea because an adjustable comb "won't cut it"), I assume your current stock is too thick in the comb area? So, you actually need more comb offset . . . not a "rollover", correct?
And all of this is independent of whether or not the stock is Monte Carlo style or not. So, if you end up buying a new stock, it doesn't necessarily need to be a "straight stock" as you said.
Please provide more detail and we'll try to help.