I love my chickens, but they do trash your garden very quickly! I have a 3m by 6m run which we got for 3 chickens (down to 2 now) and let them out supervised for an hour or so every day, which keeps them safe from predators and prevents our garden turning into a mud bath (which it did before we got the walk-in run, which I love and was worth every penny). We have an Eglu and I love how easy it is to clean, and there's no lingering smell which you inevitably get with wooden coops as things soak into the wood. The plastic coop was so successful with the chickens that we got one for the rabbits too! Makes cleaning out a doddle. It's personal preference though, there are a few different plastic coop companies (Arkus, green frog, omlet) and people like different types. There are huge numbers of wooden coop companies so you'll have a ton of choice. Be careful with the sizing, particularly if you get a coop with run attached, companies inflate the number of chickens they'll comfortably house (welfare recommendation for a run is 2sqm per chicken if they never free range, the coop itself is less of a worry because they like to cuddle up closely so will squish in)
Ours were ex-commercial girls, so they were past their peak (72 weeks old) and would have otherwise gone to slaughter, but all continued to lay daily for 6+ months. We now get a couple of eggs a week - you get fewer in winter than summer anyway. We got ours in May last year and two are still going strong, but we lost one last month. Ex commercial hybrids lay LOADS but have a proportionally shorter life span - 3 years is good going for an ex commercial hybrid. They're prone to reproductive issues because they've been bred to lay and lay and lay, rather than to live long.
We've been lucky in that we've never had a fox attack, or rats or red mite, even though I've even seen a fox in my next door neighbour's garden. Having a secure run gives me great peace of mind. We use hard wood chips for flooring to prevent mud and make sure there are covered areas too.
Also, they are really funny characters! They love to try to come in the house (they are not allowed as they poop every 10-20 mins), steal the dogs' food, peck at doors and windows, run over to see me as soon as I go outside etc. They make the cutest trumpetty noises and eat from my hand.
They are VERY cheap and easy to look after. They need water and layer's pellets and that's basically it (also access to grit/stones if they free range or you feed them treats, and oyster shell for calcium). You can leave them for a few days with food and water without problem (as long as they're secure), although if you have friendly neighbours they may enjoy looking after them - my neighbour and her children LOVE it, and they get to keep all eggs laid while they're looking after them. A laying hybrid eats about 150g of feed per day, less if being supplemented with treats/free ranging. You can get 20kg bags for £8-9, which is covered by the cost of the eggs they lay!
If you buy your chickens rather than get them from a rescue, you'll probably want PoL (point of lay), which is about 20 weeks old. They'll be on layer's pellets by then and will start laying imminently. You'll have a much wider choice of breeds, some of which have a longer lifespan (7-12 years) but lay fewer eggs. You can buy chickens that lay blue, green or pink shelled eggs for example. PoL hens are usually less friendly than ex commercial ones unless they've been handled a lot. If you go that route, definitely look online for green recommendations.
Good luck if you decide to go for it!