Can a mangekyou sharingan user awake Eternel Mangekyou, by only transplanting a pair of Normal Sharingans, or does it need a pair of MS? I know they can restore their eyesight by transplanting any kind of Sharingan, but can they also activate EMS from only normal sharingans? (not MS)
No, they cannot. It is in the manga and in the wikia. 


  ...usage of the Mangekyō Sharingan's abilities can cause a great strain on the user...it can cause considerable damage to their being, leaving the body in agonising pain and causing deterioration to their vision until eventually over-usage leaves them blind. Their vision can be restored by transplanting the Mangekyō Sharingan of an Uchiha with strong blood ties — ideally a sibling — thus awakening the so-called Eternal Mangekyō Sharingan


As far as I know, there have been no cases where Eternal Mangekyo Sharingan awakened simply by transplanting 'normal' Sharingan eyes unto a Mangekyo Sharingan user.