Any of the Martin "Tuna Cans" (60, 61, 62, and 63) would work fine on a 4 wt. Martins were my 'go to' reels back in the day...for various reasons I had put the fly rod down for several years and am now getting back into it- imagine my surprise (more like horror) to find they're out of business; E-Bay, however, is a wonderful thing.