What would be a good term for a person who has a fetish for people with disabilities? Eg, they are sexually turned on by someone with an amputated leg. Elsewhere on the Interweb someone is calling this a "devotee", but that seems to be a very poor term.
Anapirophilia (from Greek ανάπηρος/anápiros meaning person with disability) or debilophilia (from Latin debilis meaning lame, disabled, crippled, infirm) could be coined as a philia word. When I've searched the words in Google, each had a single result.
Surprisingly, anapirophilia (and anapirophiliac for the person) appears in a book about fetishes and it has the required general definition of sexual desire to disabled people. However, it adds that it is most frequently used for the sexual desire to those who lost a limb.
From the book "Curious Pleasures: A Gentleman's Collection of Beastliness" (by Rev. Dr. Eramus Croom):
An erotic fascination with invalids, or most frequently, with those who have had the misfortune to lose a limb, a practice as peculiar as it is beastly. It is also rare, and I have recorded only five examples, all male, although with so small a sample it would be wrong to conclude that the practice is restricted to that sex. However, all five have been men of cultivated tastes, which may well be significant.
Additionally, you've already found the term devotee for the person with this fetish (and devoteeism for the fetish) and it looks like the community of this fetish is using this term currently, even it has other meanings and might not sound related. Some articles use the generic phrase disability fetish.
Let me break down your question into two parts, if I am not wrong, then in detail section you suggest two different persons: a person having disability and other person being sexually attracted towards to that disable person. And, your inquire is about the latter one.
Assuming that, let's processed further to delve deeper into this topic.
A simple Google-fu suggest that the word "disability has wide scope. Disability can mean mental disability, intellectual disability, health disability, learning disability, physical disability, wannabe disability etc.
Since the disability part is still dangling, thanks to your sample sentence. It comes to the rescue and suggest that you are looking for a particular person who is interested in a person who has had a limb amputated i.e. an amputee.
If that is the case, then the such aphrodisiomania paraphilia is called Acrotomophiles. They engage in acrotomophilia.
Acrotomophilia (from the Greek ἀκρότομος "having the top cut off" (from ἄκρον akron "extremity" and -τομος -tomos from τέμνω temno "I cut") and φιλία philia "love") is a paraphilia in which an individual expresses strong sexual interest in amputees. It is a counterpart to apotemnophilia, the sexual interest in being an amputee.
Acrotomophiles may be attracted to amputees because they like the way they look or they may view the amputee’s stump as a phallic object which can be used for sexual pleasure. Acrotomophiles may enjoy the idea of dominating the amputee during couples play and they may also become aroused with the thought of having to take care of an amputee.
The article further talks about a survey,
In a survey of acrotomophiles, leg amputations were preferred over arm amputations, amputations of a single limb over double amputations, and amputations that left a stump over amputations that left no stump.1 According to Solvang (2007), “Devotees adhere to standard conceptions of attractiveness in all other matters outside of amputations.”
The word 'devotees' is used in a very loose fashion by netizens for a person who is very much interested in and enthusiastic about someone who is sexually attracted towards disable person. Until the 1990s, it tended to be described mostly as acrotomophilia, at the expense of other disabilities, or of the wish by some to pretend or acquire disability. So, if your query is just not limited to acrotomophiles, then you can use few words/phrasal words suggested by ermanen.