Maybe this thread is so old to be irrelevant but it’s a challenge that seems relatively unmet and searching led me to it.
I don’t know if people do this all the time but I’ve made several craft that use propellors to get high enough for a Wolfhound engine to be relatively efficient and then go to orbit from there. I mostly use the r-25 ducted fan blades. I end up with several hundred spare delta v on orbit usually. But this is with both expansions that weren’t released when this post was made. (But, the new parts aren’t necessarily better for very high altitude propellor craft).
Anyway I find this craft / strategy quite fun and satisfying.
