The surf is the toughest environment of all.
Inshore, we get small amounts of salt carried as mist in the wind. It doesn't penetrate except with time, condensation and slow wetting.
If you check my
rare earth magnets thread, took four years in the salt to get the first sign of corrosion in my Lew's Super Duty - only the magnets, and the bearings were pristine.
In the surf, to reach the guts, you wade out and your reel may get splashed. The splash isn't just saltwater, but also beach-sand slurry.
When the topic of cheap Sougayilang fishing reels came up on BR, I linked to a (fairly lame) youtube describing the failure of one in 15 hours of surf fishing - the failure was the A/R-release clutch lever rusted open.
Typically, those sky's-the-limit fully sealed bench reels like IRT and VanStaal belong here - at least a Tsunami or Tica.
That said, Daiwa SG is a good choice (Tica makes a good portion of Daiwa reels, and very likely the SG). I haven't looked at a Daiwa spinning reel schematic in awhile, but I bet it shares a good sealed clutch.
fwiw, when I order HCRB salt-resistant bearings from Hedgehog, they always send Daiwa mag-seal.