Well, if you plan to sell it, you need to pay your developers and not even be looking for free help at all IMO.
I am designing a program from scratch myself and found SourceForge a good place for that. But even there, the volunteer help has been scarce and the ones that did help, did a little and disappeared. One even had ideas about wanting to sell my program and when I bucked it, they disappeared too, lol.
You might as well learn the languages and get it over with, lol. I have found that to be my solution. This way I can be sure the program is doing "exactly" what I want it to do. Will it take longer to finish? Oh Yeah, lol! Will it be worth it? Absolutely!
Just my thoughts...............
I'm old so don't disrespect me, lol!