This is a typical scenario, one owner encloses a patio/porch, the next insulates and puts electric, the next replaces with nice windows and carpets, the last has to deal with problems. At least your walls are probably only bearing their own weight, but who knows about the roof support having a proper foundation. Probably a 3 1/2" patio slab at best, with level grade, so you will never stop ponding. But you should really try to get the grade lower, I imagine you'll never get 4"-8" below though. So . . . it doesn't matter about raising the old sill plate, you'll still have issues, so just replace it with a double plate and put a membrane outside like the photo above.
If you really want to shim, "common" brick just differentiates it from "face" brick. What is important is an ASTM C90 designation, which specifies load-bearing capabilities. Very few, if any, bricks at the big box will be that, especially not pavers. Either a 2 1/4" high CMU ("common brick size" or "structural brick"), or a 2" nominal (1 5/8" actual used as a soap) CMU would be better. You'll have to fasten the wood sill through this shim to the slab to prevent wall kickout, but again, all this trouble of mortar, drilling for anchors in a 3 1/2" slab and shim, and membrane doesn't get you anywhere better if you can't lower the grade.