Yes and yes a good quality any brand will do. We use an electric and petrol one at work and just add the same oil for both without issue

Ive just used some random bar and chain oil in my ryobi expandit one, but its barly seen any use since then as now the offending trees are not overhanging so I do not need to trim them again for quite some time.

I used random bar oil in my Ryobi one+ chainsaw. 

Cruciblewrecker: Related question are the Black and Decker 18 volt Lithium Ion cordless pole pruners any good? Because I am looking at buying one from Mitre 19 Mega tomorrow.

I have one. They are awesome.

Very light weight, low maintenance. I install broadband rooftop dishes, and one of the problems we had was trees blocking the signal. Now we can just pull out the B&D one without needing to keep the smelly petrol chainsaw in the van. And its great for worksafe because we dont need to get on a ladder and fill out another job sheet to cut most intrusive branches.

Get a couple of extra batteries though. They dont last long on a charge.