Is dealing with a bank that buys cows and equipment for a cattle breeding project, then sells them to the client in monthly installments with an increased profit margin the longer the repayment period, considered usury (riba) or شبهة الربا (something akin to usury/doubtful transaction)?

If the bank offers the client different payment period options with a corresponding profit rate for each period before the contract, and the client chooses one of the two prices, there is no harm in that, provided that the price is not increased if payment is delayed. The bank's purchase of the equipment must be a genuine purchase, entering into its ownership and responsibility, and then it sells it to the client through a separate contract, to avoid circumvention of usury (riba).