any grade oil at start up will be fine, 1st change after 1000 kms shall be 5W-30 or 10W-30.
parts pricing is a high variable. there are few auto parts dealer who throw buyer in spin and sell C grade item. Only an seasoned mechanic or the machine shop guy twist their arms for crackling sound. That is why we at PW always recommend to do parts shopping along with mechanic to know if the monies are used wisely.
at Plaza Karachi you can roam around haggle & irritate seller with all questions of oem, japanese, malaysia china class, at Al Nasir Motors over main M A Jinnah road next to Puri Glass shop., Malik Autos (aamir malik) opposite preedy police station shops, Al-Furqan Motors at ground floor of Tibet Centre & across that Japan Autos. All these guys are '2nd generation auto parts importers / sellers' their suggestion is worth consideration.