There are a few out there like this, but so far this ALLPOWERS brand is the only one I can find that seems to have a 240v output (at least according the product manual): ALLPOWERS R3500 + B3000.
In THEORY it has 3500W output (at 240v) and 6.3kWh of capacity with the add-on module, but I wonder...
I think I found the first ever Stark race result from Cahuilla two weekends ago! Hopefully I'm not stealing Bryan's thunder here but it looks like he did pretty good - maybe 2nd before it got red flagged? And in the fastest class too!