Need help finding a barrel for trap

I've recently purchased a Remington 870 Express Talo edition (pic attached), which has an 18.5" barrel. I've had fun shooting trap so far with a short barrel, but I expect I could benefit from having a longer barrel. So here are my questions:

1. What's an ideal length for trap and possibly some skeet?
2. There seem to be a plethora of barrels out there, what do I need to look for in the name to make sure I get one that fits my shotgun? Does the barrel just need to be for a Remington 870 Express and it should fit?
3. Do I need to know anything about chokes?
4. Why do they all seem to be out of stock everywhere right now?

Thanks all!

A 28" Express barrel should suffice. You will need to figure out what to do with your mag tube extension, but that shouldn't be hard.

The barrel comes with screw-in chokes. Typically, for Trap, you'd use Modified or Full, and for Skeet, you'd use Skeet.

What ArmedBear said, or if you want to save some money, get an older fixed Full choke 28" or 30" Wingmaster barrel and spray paint it with some flat black to match. The older 2-3/4" chambered fixed choke barrels, even the vent rib ones, are going for less than new Express barrels.

If you want to try Skeet and Trap with the same gun, the screw-in choke is mandatory.

Do NOT buy a barrel without a rib, especially if the bead is on a pedestal. Waste of money.

If you are going to swap it out for a long barrel, the mag extension will get to be a pain in the butt going back and forth.

A used barrel is generally going to run $100 and up. On occasion, you can find them cheaper than that, but you are looking at 50% or more of the cost of a used field gun.

If it were me, I would leave that gun as is, and look for a used gun. Around here, I've seen used Expresses and Wingmasters between $200 and $300 for mechanically sound guns with a little character. The last few express guns Ive seen had choke tubes, while the wingmasters were older and had fixed chokes.

Just something to think about.

get a good 28 inch vent rib barrel for trap, the gun should be good to go for skeet the way it is, i know alot of people that shoot skeet with their old remington police/riot shotguns.