I got a contura 510 off of eBay, for £300 (normally about £800) and another well known make that I can't remember, and that came in about half price to new. I just kept looking and reading reviews, and these two suddenly came up. Parts came in about £500, and I fitted them myslf under a building control notice for £144. Ideally you'll have scaffolding, or you need a roofer to get the liner down the chimney for you, but it'll end up swings and roundabouts - depending on the access to the chimney of course.
Stove, closure plate and brackets, stove pipe to closure plate, chimney liner, and cone to pull down liner. Insulation (about 5/6 bags of vermiculite) is a good thing to have, but you need the chimney pots off to do it, hence scaffolding that gives you a day or two is good. Then you'd need a chimney support plate and bracket, then refit the chimney pots, then cut the liner off at the top of the chimeny, and fit a downdraft cowl.
I just researched each stove on offer, read as much as I could, and then jumped at those 2 when they came up. I took out the old brick hearths, leveled them with self leveling compund, then cut and fitted some ceramic tiles to make a new hearth. Not perfect, but very satisfying. Bought one of those fans from Aldis, didn't notice any difference, so took it back; not sure if the better quality ones are any good though.
And if you're getting a hot smell from the stove, it's often because the wood hasn't been dried enough, and the steam being produced from the damp wood will overheat the stove.