Well 99% of ferrets out there will be neutered & descented, so you probably won't have a choice unless you try and find a breeder. Most ferrets come from Marshall farms, who breeds for all the stores and for research labs. I adopted by two from a shelter at 4 months old and they were originally from Marshall's farm. One is deaf, and I don't know how, but both came essentially litter trained and never nipped except each other.
Be prepared for HUGE vet bills - adrenal disease and spleen issues are very common as is insulinoma. All of these are pretty expensive to treat and its essentially guaranteed you will face one of these awful cancers. ADV is another disease to watch out for.
Also, I'd recommend a trio - sadly when one passes, its easier if they had a buddy and hopefully the two remaining would end up passing around the same time or you could add another. This is why I won't be getting another ferret because one always ends up alone or you have to keep getting another and another. Regardless of the amount of time I can spend with him, nothing makes up for having a friend. I'm just not his size and he is so gentle with people that he doesn't wrestle - he does love playing with dogs/cats)
His sister lost a ton of weight in a very short amount of time and despite making the soonest vet visit, she passed just hours before the appointment. We believe she caught something being boarded at the ferret rescue who ended up closing(she was so careful about health/separation before, but this past time she "lost" my ferret who ended up in another cage with another group!), but the vet didn't feel it was contagious(we had Gilly examined afterwards and monitored him closely).
Definitely keep them away from the suggies as ferrets are predators. They need a big cage like suggies but the bar spacing can be wider - I'd highly recommend the Ferret Nation cage! The doors are huge for easy cleaning :)
The smell is definitely also an issue - food helps(see diet info below), but they eat a ton and then poop a ton, which is the smell that bothers me as they don't cover it like cats and you can't use traditional litter as its toxic for them. Descenting really doesn't cut down on their smell much(neutering does!)- descenting stops them from releasing their glands when they're super excited or scared. But they also produce a lot of oils that have a musky odor. I don't mind the smell of him because I wash his bedding often, which is the best way to reduce the smell, but it does bother a lot of people so make sure you are OK with it. I'd advise visiting a petco and smelling their cage - if you feed them right and wash their bedding, yours will NEVER smell that bad, but it can get quite strong and vary based on the seasons. Oh, and CLEAN their ears!!!
Also, make sure you know their diet needs - find something very high protein - you can use grain-free, high-protein/low-carb cat food or there are some good ferret foods on the market(and some not so good!), but ferret food comes in tiny bags and the high-protein cat food is what my vet recommends. He also recommends rotating foods or feeding a mix as not one diet is complete AND if one brand changes(which they often do!) you won't have to worry they won't eat(as they can be very picky and starve themselves for awhile).
Providing them complete darkness for 10-12 hours a day is supposed to help with adrenal issues, but I don't think any definitive studies have been done about it. I tried to make a cover for Gilligan's cage, but it still let light in and for the sake of making sure he was able to interact with everyone, keeping him in my room was more important even if it isn't 100% dark.
I just can't stand falling in love with something to know they won't be around very long - especially an animal with as much personality and quirks as ferrets. I'm sure there are some breeders trying to improve longevity and reduce cancers.