You don't have the right speakers for that room and they cannot be placed where they need to be placed. If you have a very tight budget, it does not matter what we think. It sounds like you need someone on-site to help you make the most of it.
It is a small church. Don't worry about it. If someone gets bent out of shape, given the circumstances, let them belly up for new gear. Until then, keep the seating area restricted to the front 50" of the room. If you are up-front with people, setting their expectations for them, you will have less complaints coming your way. Just tell them that they are now in a building that was never designed for a loud service with a PA. You are using a bunch of things for an unintended purpose, and things will be janky for a while, until you can address the acoustics and sound system properly.
The DriverackPA will only give you processing for the mains and subs, but not the monitors. It does not have discrete assignment and processing for the two inputs. The 260 does, hence the difference in price. You will need some EQ for your monitors. Whatever you do, don't rely on the Driverack to set the EQ in Wizard mode, especially if you do not know what you are doing. You will have blown speakers in no time.
Find a local dealer with a good tech. Call some other churches with tech people on the payroll. Get them to consider it ministry to help you set up your room. You are not going to get a reply that makes your system scream. You need someone to be there in person.