I always do an oil flush when I buy a used car. I've torn down engines before, and this stuff really cleans out the varnish and crud that accumulates over time. If the PO skipped an oil change and varnished things up, this helps get rid of it. It's your choice, but I've always preferred to keep those bearing surfaces clean for the oil to get in there.
I ran the engine for 5 minutes and noted that the valves started clicking pretty loudly at the end. Once the new oil was in, I idled the engine for a couple of minutes and the clicks went away.
The plug wires seem reasonable. They aren't a perfect fit length wise. One was extra long. They are probably sold to fit both early and later rovers which have a distributor or direct ignition depending on the year. They are half the cost of Magnacore and easy to get.
I chose spark plugs based on availability. I've since checked the RAVE manual and noted that Champion plugs are OE. As long as they are the right spec, it doesn't really matter what manufacturer you use.
The air filter is will not show up as the proper filter for the rover. It's actually double the size of the standard filter, and seems to have thicker walls. For $10 it's a great upgrade.
The air filter is typical. I considered a k&n, but opted for traditional filtration.
Epic Oil Changes
I ordered 3 gallons of oil. Enough for about 2 oil changes. (I like to keep stuff on hand for good weather days) Again, synthetic oil is optional, but it's well established that it's better than conventional. My shipment from amazon leaked and Amazon sent me replacement bottles for my entire order.
I learned the hard way that changing oil is a bit of an epic challenge. You need a 1 and 1/8 inch WRENCH to remove the oil plug. My 1/2 inch socket wouldn't clear the exhaust downtube. I committed the sin of using a crescent wrench.
A proper wrench is on order.
The oil plug is huge. This means that a normal oil drain pan won't cut it. Mine was overwhelmed. Fortunately I had a bag of cat litter handy to stop the environmental disaster that ensued. Purchase an open top drain pan like this one.
The new purolator filter has a nut built into the end. You won't need a special tool once you get the old filter off.