Firing Line will be out soon, and I GM'd Ashes, it played out just fine with starting characters thanks to a bit of GM guidance. However, you'd have to convert the IC, though I posted how I did it somewhere.
Of course Humanitarian Aid and Carbon Copy are a bad idea for new players, but still, that's 2 quite doable for starting players, Firing Line out soon that hopefully will have a few more nice ones, and an intro with Fast Food Fight. And a few nice heavier ones for when you want a challenge later.
Just keep in mind Missions are mostly balanced around a party of 6 people, so if you use any with a significantly smaller party, the GM should definitely consider tuning the enemy count back a bit.