<i>I agree, option C would be a poor choice. </i>
Why? Plenty of EMUs elsewhere in the world work like this just fine.
<i>"If it ain't broke don't fix it" as the saying goes, the M-8 should be based off of the current Cosmopolitan cars, with the Bombardier body. </i>
Forget it. The current propulsion system is a disaster, and in any case, the cars would be far too heavy.
Even the existing proposal is gonna be a challange to get working decently. I'll be surprised if the third rail performance of them is any better than the existing cars, and I'd place my bets on it being as bad, or worse. They'll have '1000' HP, but there's no way they'll make that much in DC mode, as the M-7s have shown. Rationally, assume a pair of M-7s at 700hp a piece, and 375,000 lbs, that works out to 7.4 HP per ton, or slightly more than the ACMUs. In short, they'll likely not be able to hit 80mph on DC mode. Even in AC mode, they'll only have about 10HP per ton, so they're not gonna be really fast anyway.
With every car powered, assume 150,000 lbs per car, and about 700hp max in DC, and maybe 1000 - 1200 in AC. And that's being generous, and assumiong all cars functioning. tHe HP:ton is better, but the overal power consumption will be much higher.
Or, go the other way, and assume a max weight of 100,000lbs per car (likely impossible under FRA regulations). Going again with the same 700 / 1000 HP numbers, that yields 14hp per ton in DC, 20 in AC, which is significantly better than today's stuff (assuming all cars powered and functioning). You'd be able to chop the CT portion's schedules a bit with that much. Drop down to 80,000lbs per car, you get 17.5/25, which could likely allow a major schedule improvement - imagine equipment that could outperform an Arrow III by a bit. Keep dreaming - it's impossible under existing regulations.
Don't expect the M-8s to be any faster than the current stuff, and they'll probbably ride just as bad, too. They'll use more power though, so your fares will go even higher...