Not familiar with your lathe, but if you would consider it a light duty machine, you probably want to go with positive rake inserts (for example, TPxx instead of TNxx).
If your lathe is heavier, you can use negative rake tooling and get twice the tool life because you can use the other side.
Look at what the inserts cost - you will buy the boring bar once and inserts a bunch of times. I once picked up a boring bar cheap and the inserts were like $30 each.
T inserts are popular (probably the most plentiful on places such as ebay), as are C. C is stronger because the angle is 80 degrees instead of 60.
Go here for the secret decoder ring of inserts and toolholders:
Carbide Depot Technical Resources
The W insert I think makes the most sense, as you get three corners but they are 80 degrees, but they are quite a bit more expensive.
For my shop, I've settled on three inserts:
T - because I can get them cheap
C - I inherited a bunch of boxes, bought some toolholders and they work pretty well
V - for when I need to get into a really tight space.
I'm going to get one tooholder for square inserts so I can have a 45 degree chamfer tool.
Also, when looking for inserts, look at the grade as well as the size. Some are better for steel, some for cast iron, some for alloys. Carbide depot has a grade lookup. When you get the box, write on it what it is for, as you don't want to go looking up which is for stainless when it's time to start turning.
Steve