I've have the same rod for about a week now and I would say go with the Rio 375. While shopping for a line, I got to test an Airflo Skagit Compact 420 with a long sink tip on it and it felt a bit heavy although I was making 60-70 foot casts with it,(singles, doubles, snake rolls and snap-t) I think I may have been overtaxing the blank. Remember, you're adding grain weight with a sink tip. I happen to like the Airflo lines and settled for Aiflo Compact 390. They also make a 360 grain line. The Manufactures recommended grain window is: 210 to 440.