No need for plugs or a coolant change at 7500 miles .. at most , oil , oil filter , check airfilter and change if needed... if not blow the dust out and put it back in.
The rest is just checking stuff .... chain tension/lube , tyre pressures , fluids Etc ..
As for using oem stuff , well I'd use good oil at least and the oil filter doesn't need to be oem .. if replacing airfilter I'd put in a re usable one like K&N ..