I know precisely the bulbs you are reffering to, a lot of more modern fords and other makes are fitted with them, as so many pillocks couldn't even put a tail/stop bulb in correctly, so they had 1 "brake" light showing when is was driving along.
I think the small car company may do the ones you want, otherwise you could do what I have done before and fit different bulb holders, just cut away the bulb holder strip as needed, resoldering any wires/tracks that needed cutting, can use the parallel pins ones then, you could even then use a " stand off", in place of the bulb base and then use MR11 bulbs ranging in wattage from 3 watts up to 150watts.
tabetha