Kilrain, if you're someplace where it's warm and sunny enough that the lawn needs mowing, I greatly envy you...
The best accessory one can have after buying a "Serious" shotgun is a case of ammo. Use up, repeat, until the weapon feels like a body part. Then, one's in a better place to decide just what addon or mod will aid the mission and what's just another Wallet-Vac.
Unfortunately, we Americans oft think that technology can substitute for expertise. Almost always it can't, but we keep trying.
If you have access to a fully accessorized "Serious" shotgun, try running a good,reality based COF with it for time and score. Next, run the same course with an out of box shotgun. If your scores and time vary more than 10%, the donuts and coffee's on me.If it's more than 5%, I'll still buy the Krispy Kremes.
Then, switch strong hands and run that same course off sided.If you shoot RH, switch to lefty. Score and time that. Unless you've serious eye of hand probs, you just got a cheap Satori on the inportance of expertise. And, the relative importance of bellsnwhistles.
I'm certainly not against mods and addons. But, real world priorities show that a trained and cool hand can shoot anything well(within reason) and a dud can't shoot worth beans. Extreme cases, yes, but life's full of extremes.
As for lights, that's a sore point. I recognise the need, but all the good ones cost more than my shotguns do, and all the ones I've tried and handled made the shotgun handle like a pig on a snow shovel, to steal a good line from Bruce Buck.
(Dismounting from soapbox)....