Depending on your level of pain tolerance and fastidiousness:
Both the Bowser and MTH Brill trolleys are too tall, made to accommodate existing drive units.
This compares a scale Brill semi-convertible trolley side to the MTH Brill. The extra height seems to be in the tall windows with lowered sides:
The truck wheelbase is an excessive 7'3". Still, the MTH is RTR and relatively inexpensive; they show up on eBay from time-to-time. Getting a scale version is work:
The kit needs clean-up plus a roof and floor plus power plus poles plus details (from Q-Car). I'll have close to $200 in it before I'm finished. The Brill is cute but out of date for "contemporary" schemes.
The Corgi PCC and Birney cars are slightly undersize at 1:50 scale. If you don't need to preserve interiors Bowser offers power units; otherwise it's off to Q-car or GHB.
That's pretty much it for available streetcar models (plus the WBB Witt cars) unless you opt for the Bump-n-Go versions or the noticeably subscale Atlas car.
After that you can get into large money, based on eBay selling prices for scale trolleys. and you typically have to buy separate power trucks. These prices make me wonder about the so-called dying O scale traction hobby. Maybe it's comprised of 25 rich guys
