If you go for sows, you have to face ovarian cysts, which are a lot more common than impaction although thankfully many go unnoticed and don't cause any problems. Not quite so yucky, but rather expensive!
Sows: Behaviour and female health problems (including ovarian cysts)
Boars, sows or mixed pairs; babies or adults?
When you look into it, there are no 'easy' and service-free pets. Whatever species or gender you get, they require commitment and they all come with their own problems, some of them yuckier than others. There are also no cheap pets; with all of them you have to save up from the start as an integral part of their regular living cost so you can afford emergency vet care or alife saving emergency operation at any time. This can quickly run into the hundreds of pounds or dollars, whatever the species. There is unfortunately only limited or no exotic pets insurance for guinea pigs because they are still considered by too many people as short-lived children's pet not worth spending any money on, even though they have an average life span of 5-7 years and generally far outlive their welcome.
It doesn't really matter what gender or gender combination you get; they all come with their individual issues. Any pet needs regular checkover, irrespective of the species. By homing in on one minor potential gross aspect you are going to miss all the good that boars can bring. By staring at one particular tree you miss a whole forest through which leads a path that likely never comes close to that particular tree. You may notice that you haven't been swamped by members telling you about their own impacted boars... That is because they are not exactly all that common!
Dealing with yuck is usually simply a matter of getting over it and on with it, whether that is as the mother or older sibling of small baby, the wife of an ill husband, looking after your elderly parents or relatives or as carer of a pet (guinea pigs thankfully don't vomit). Sooner or later in your life you get confronted with it. A pet is not the worst place to learn to get over that particular hurdle and then find it much easier to deal with a human emergency in your family at some point in life. Like a previous poster said, you do it because you love somebody, whether they have hairy or bald skin.
PS: Neutered boars can still get impaction, but it is not as bad since they haven't got the large anal cavity that is created by the descended testicles. I've just lost my Nosgan, who was suffering from impaction caused by a hernia, which in itself was a thankfully rare late neutering operation complication (he was already neutered when I got him although in his case it was not important as he was going to be a companion to spayed sow), just as an example that all your choosing and planning now won't necessarily go to plan in real life! Life has its own ideas. Learning to deal with what it throws at you and coming out stronger at the other end is more important.
If you are asking because of a specific pair of boars, then please get them and give them a happy and loving home with good care; but only if you are ready to commit to the ride, whatever it brings. If you are not ready, then please consider whether any pets are for you since you can never choose in whatever species (including human company!) what illness or problem you'll end up with; but it is rarely a bed of thornless roses!
I've spent a couple of years of my life with my husband being repeatedly very sick and not able to control his digestive noises from an ongoing gallstone/bile duct problem and all the somewhat massive complications and treatments arising from that. It is not something I would have chosen (who would?), but love and a commitment to your partner gets you through the rough bits in life. The same goes for any pet you forge a real bond with.
Sadly there are in this throwaway culture too many living beings that are being treated like disposable toys, with their owners unable to commit. They do miss out on something important however; emotional intelligence and the capacity to feel empathy for the weak and defenceless, which makes us much more mature and richer people.