I agree, If you want to go with all Mono, get Momoi Diamond 50#, I think its actual breaking strength is around 83lbs, but it has the same diameter.
If you want to spool up with any kind of spectra, I highly recommend Jerry Brown 80 or 130. I go with 700 yards of 130 with a 100yrd topshot of Diamond 80 (actual breaking around 100)
The only problem with fishing the 12-15lb drag is that you risk a big fish taking it to you and getting spooled. You can put 1100 Yards of JB 80 on a Penn 50W, and 1300 on a Shimano50W. (800 and 1000 of 130 respectively)
Those capactities for spectra are based on a 30ft topshot. So adjust accordingly.
Just some ideas. If you want to pursue spectra, contact Tek at Reel Pro Shop.
www.reelproshop.com