My day job is working with disabled people including people in wheelchairs. Most of those people are in relationships and most of them met their partners after they became disabled.
from what I can tell the same factors that influence relationships with abled people influence relationships with disabled people. If a person is clean, neat and friendly a wheelchair does not seem to matter.
In fact most people in wheelchairs seem to do better with relationships than most computer nerds that I know

@Lukas the evolutionary pressures for relationships are about forming stable partnerships not about hunting or breeding. in all monogamous relationships the evolutionary imperative is to find the personality that will form the strongest union. in essence a weaker partner who is reliable is of greater value than a handsome strong partner who is unreliable.