Energy Usage, Conservation and Weather Stripping - Cold windows-- get custom storm windows?

I live in a 1-yr old gut renovated condo (limestone building about 80yrs old) in NYC, ground floor (above a cement-floored basement). Unfortunately for me, the HVAC ductwork was run at the top of the walls (8.5'), with no floor registers and so the apartment is generally cold even at 70degrees.

My biggest concern is a back bedroom (7'x13') in an "extended part of the building, which is consistenly 10d colder than the rest of the apt. Two walls are external, and there are three "double paned" double hung windows. I used the plastic sheeting last winter, which other threads have referred to; however I would prefer to get storm windows. My question: I can't find the make of the windows, and the developer won't return my calls! Should I get custom windows for the window track, or the old fashioned kind my grandparents had, which hooked onto the outside of the frame; or is there another affordable solution?

In the LR there is a standard sliding Andersen door which is also very cold: is there a "storm sliding door" ? The door frame is deepset, and I could literally put in a second door in front if that is advised, even if unusual.

Secondly, does anyone have experience (pos or neg) about ceiling heater fans? A carpenter friend swears by the one in his kitchen, over baseboard heaters...

The ceiling of the basement room below was already determined to be inadequately insulated, so I am obtaining estimates this week on that work (sadly, don't plan to DIY)

Thanks greatly in advance for any input.