JSFfan,
Sorry, not sure I understand. Under what circumstances do you Need supersonic STOVL stealth strike fighter? It's not clear to me that the USMC needs anything more than an updated AV-8B II+, because any time a MEU will go in somewhere that has the odd SA-20/SA-17/SA-22/SA-24 IADS with evolved FLANKER / J-20s, controlled by KJ-200 AWACS, then I think it's pretty likely that the USN will send a CVN (or three).
And if you don't face something as complex as that, then a Harrier would be fine.
S41