tips for where ? you need to be more specific because I will use anything from a clear sink tip all the way to T11 depending on the depth and/or speed of the current
you wanna cover all your bases then so buy these
floater, clear tip, type 3, type 6 - These come in a wallet set from Rio and will save you over buying them individually
type 8 is sold separately now, it used to come in the package but they changed it a couple years ago
12-15 foot chunks of T11, T14 - you could also get T8 but it sinks the same as the type 6 so there really is no point in having two tips do cover the same water column
I would buy the T tip though because T (tungsten) sink tip material comes on bulk spools so its a lot cheaper and you can get it cut to whatever length you want. the # designation is NOT the sink rate, it IS the amount of grains per foot (#11 - 11 grains per foot)
here are the sink rates for the T# tip material
here are the sink rates for the "type" tips. note that the # designation IS the sink rate
Clear = 1.5-2inches/second
type 3 = 3-4 inches/second
type 6 = 6-7inches/second
type 8 = 8-9inches/second
Im sure the sink rates for ALL these materials is done in water that is not moving so don't expect them to sink this fast in moving water however it will be somewhat close especially when you mend properly it may even sink faster as the current helps pull it down.
I hope that is enough info for you guys