OK - got it now. It is never recommended to use exterior paints inside, unless they are explicitly for indoor and outdoor. Pure outdoor paints contain fungicides and mildewcides, nasty chemicals that can trigger allergies and such.
SW ProClassic only comes in an explicitly indoor formula, but it will work just fine on an exterior door surface as long as the two colorants I mentioned are not in the formula (fading is the only risk). A packaged white can of ProClassic is just fine for your door.
ProClassic comes in two varieties, waterborne and alkyd (oil-based). I personally have used both formulas, and I'd use waterborne hands down for the ease of use. It really does mimic the smoothness of ProClassic alkyd, and IMHO is just as durable. Plus, it doesn't take

forever to dry like oil-based. Just put a foam roller to work, or spray it if you can, and you can get very smooth results.
Bonding Primer is a latex product, but I don't believe it will interfere with oil topcoats - check with the label or SW to be sure. If it won't, you can try SW ProBlock Alkyd (Oil-based). Of course, if you go with ProClassic waterborne, I know there will be no conflict with the Bonding Primer.