If I were you, I would go out and pick up a RIO Versi Tip System.
The Line is a running line that is 15' short. It comes with a loop on the end of the line and on the end of the tips. You do a loop to loop conection, and there you go.
The Versi Tip comes with a Floating tip, Type I Sink Tip, Type III Sink Tip, and a Type V Sink tip.
This way, you have all kinds of water conditions covered.
Now, you asked what sink rate would be best, that is hard to answer if we don't know where you will be fishing. I would look into a Type I and then a Type III
The other way to go is to pick up some Versi Leaders, they come in many different sink rates and are only around $8 each.
Here is a link to them on the RIO site;
http://www.rioproducts.com/product.php?fmCategory=22Rick