Hello hello!
Yes I do have chickens (yes they were eaten by a fox but bought some new ones the next day - couldn't bear the thought of buying eggs in a supermarket again). I have one of the Forsham cottage arks to keep them in - the Broughton - and they are very happy and lay beautifully. You don't need a rooster - wouldn't advise getting one. If you want to go on to brood your own chicks you can always buy fertile eggs for about £1 each, roosters are more hassle than they are worth (and noisy).
My hens are super easy to look after - they have their feed in a hopper so it only needs refilling every few days - get a BIG water thing, as they drink a lot of water, and then you won't be refilling it every two seconds (more like every other day). 4 hens gave us 4 eggs a day through the summer, more like 2 eggs per day in the winter (but that is from good layers, like the various hybrids, or white sussex, or marans - not the really fancy pants ones which look lovely but don't lay so well). They do poo a lot, but mostly at night, so lay newspaper under the perch and then once a week or so chuck it on your compost heap. Great fertiliser.
I recommend an ark, because you can (A) keep them in there all the time, if you have a serious daytime fox problem like we do (bloody local farmers won't allow hunting over their land and don't shoot them, either) and (B) you can move it every couple of days so they always get fresh grass (v good for their eggs) and it also means that you don't get a permanent manky scratched up bit of ground that the run is on, which attracts rodents and looks and smells horrible. By moving every couple of days they just fertilise the ground and your lawn looks great. That is assuming you aren't going to let them be completely free range, which is another option, but it makes it tricky to find the eggs and the fox will get them sooner or later.
your hutch would be OK for small bantams, if you can install a perch which gives them head room to sleep (just a few inches off the ground, but make sure it is the right size and comfy for their feet). Also check what your hutch is roofed with, because if it is roofing felt you will have to change it - it will be a breeding ground for mites which your chickens will be v unhappy with.
Phew, think that is it for the moment! Have a good look at the forsham cottage arks site, it has a very amusing section on keeping a few chickens in the garden. May I also highly recommend a deeply spoddy but hilarious publication called..... "practical poultry"! Monthly, and worth every penny of the £2.20 it costs!