Ideally with your setup, id go with 3 and 5 woods. If you can only get one at the moment, get the 5. Its great/ideal for longer par3s and is easier to hit off the fairway then your 3 iron. Plus youll get about 15-20 yards up on the 3 as well. Then when you get the chance, get the 3.
You can see in my sig, thats my setup (although i have a 2iron instead of the 5 wood, personally like irons a little more, but the 5 wood will help SOOO much on long par 3's).
(^^^^ Demon posted while i was typing mine
, he's right though, 3 wood and 5w or 2i^^^^)