The simple answer is no. The "performance" they are looking for is not location accuracy when everything is perfect, it's how sure the GPS is of that accuracy at all times, even in degraded situations. This is not a function that commercial GPS units generally provide to the accuracy and standards the TSO requires.
The point of ADS-B out is to keep two aircraft apart, so your IFR or VFR doesn't matter. ATC has to keep that airliner that is IFR away from you when you are VFR, and they need to know your location is accurate. That's why the only three things in a home built that must be certified are the transponder, ADS-B out device, and the GPS. They're the things that don't just keep you safe, they keep the general public safe.
On top of all of that, serial protocols like NMEA flat out don't include the data needed to transmit the ADS-B data, so even if you hooked one up to your ADS-B out device, which must be certified, that certified device won't transmit that data as certified.
ADS-B out is not required for another 2,442 days, and even then it's only required in places where a transponder is required (class B and C airspaces and above 10K feet). That's a long time, and TSO'd GPS prices are likely to come down before then. So why worry about it today?
If all you want to do is "wake up" the ground stations so they will send you traffic, you can use a non-TSO GPS today up until 2020. The ADS-B out data includes data about if your GPS is certified, so the world knows how much to trust it.
--Ian Jordan
Dynon Avionics