Turn signals are PY21W and the side markers are W3W in the 987. I do believe that these bulbs are exactly the same as the 986's so you'd be fine in doing that.
By the way, if anyone's ever looking for bulb information, this site is a fantastic resource:
http://www.donsbulbs.com/cgi-bin/r/t.pl
That's how I found out that the Euro W3W is the same as a US 194 and the PY21W equates to a 7507.