Can a child that is 7 in Texas make a choice to live with his father?

It's not likely that a judge would take the wishes of such a young child over the evidence presented as to how the best interest of the minor child can be served. The parent that can demonstrate that they have the most stable and nuturing home environment is generally the one that receives primary custody. Financial issues are not a part of the decision, (or shouldn't be). The non-custodial parent will generally be ordered to pay support that will help to maintain the same lifestyle the child would have experienced if the parents had remained together.