There are different sink tip strategies. Here is how I look at it.
Slow current, small moving water - short sink tip (10')
Slow current, big moving water - medium sink tip (15')
Fast current, small moving water - medium sink tip (15')
Fast current, big moving water - long sink tip or integrated shooting head (24' to 30')
Then choose an appropriate sink rate.
For this kind of water, these guys were using 24' foot 175 to 200 grain sink tips to efficiently fish a holding area that was four to six feet deep. The water flow was rated at 5000 cfs that day. There was one section that was really deep. A 325 grain sink tip was used to get a fish from that hole.
If you are going to fish lakes, consider a full sinking line rather than a sink tip.