How come you don't want someone serious who wants to make poker their main income? You say it has fell through in the past due to horse not having enough time to devote to pokes, so would have thought someone who has a load of time would be ideal?
This.
Considering during worst times the most motivated and serious poker players struggle to sometimes meet the hours required and incentive to work on their game I think out of everything you have suggested, this is the only issue.