You need to store cut logs for a lea[list]st 12 months in a dry store to season, otherwise tar deposits can build up, leading to chimney fires, so trips to the local forests need to be planned in advance.
Installation should be done in a day, so costs shouldn’t be too high. It’s an easy job, just bricking up the hole for the flue, unless you can get your hands on a 225mm core bit( most hire shops should have one) . If your any good at DIY its defiantly worth doing to keep costs down.
I’d go with 150mm flue as most fires use either 125mm or 150mm, and will work with a larger flue but not a smaller one.
If it does go through a cupboard it would be worth putting a vent in as the flue can get very warm.