Help me to choose the right cam

Just for reference, my 360 powered W250 has the XE262. I have twin 60s with 4.10s and 32s. If that engine has ever been over 4K I'd be surprised. It's snappy, has a little lope to it, and has a ton of torque at 2K. I use it to push an 8' Meyers plow and pull a car trailer. Even pulling a loaded car trailer up a 10% grade for a couple miles it doesn't need to rev.
My advice - ignore how it idles. It will sound cool anyway with a 440 and performance mufflers.
The XE284H is too big for your use going on your existing gearing and tires, never mind bigger ones. It's also a mismatch without running headers regardless of the tires and driveline. If it was me I'd go no larger than the XE262. I think the XE256 is another good choice but it will leave a little on the table even if you're cruising around at 1800rpm.