The 147s are intended for passenger use and have quill drives for a top speed of 160km/h. The 187s are intended for freight use and use axle-hung drives for a top speed of 140km/h. I read Bombardier also offers the TRAXX AC3 F140 (Br 187) as a F160, which has axle-hung drives for a top speed of 160km/h.
147 have PIS, 187 don’t (that is probably obvious now it been said above one is passenger, but it was a talking point about the 187 in TSW so thought I’d mention it , about how easy it was to convert it to a 147 with PIS)