the ranger set consists of
gloves in Act 2 ( you got them)
Armour in Act 3 ( quest reward)
Belt in Act 3 (quest reward)
bow ( hidden in Act 3 in the ware house) I used Rapid Shot for a long time
another bow (unique item) may be nice for your rangers => Eradicator, you can get this in Act 3, too. By stealing or killing).
Point in collecting? None, I guess - not at the moment. Only one, most items are indestructible - or were so.
Kiya