Sadly, I don't have any answers for you as I am not skilled in this area. I do want to encourage you for it is a beautiful thing that you do. Thank you for doing this.
You are already one step ahead as you appear to know the Qur'an. Muslims will not have read the the OT and NT. The NT predates the Qur'an by several centuries and was accepted as scripture long before Muhammed had his dream.
You could also take the approach that Muhammed is not your prophet, Jesus is and state that this is what Jesus says. Also Jesus actually did what he promised he would do. Muhammed never made any claim to die for the sins of his people.
Off the top of my head a couple of websites that spring to mind are: carm and bethinking. I can't remember the actual URL's but google should take you there.
Hopefully someone with skill and knowledge on this board will read your post and respond.
Blessings

__________________
Donnie MacLeod
Crossroads Presbyterian Fellowship (PCA), Maplewood, MO
MDiv Student Covenant Theological Seminary

You filled my heart with greater joy
than others may have found
As they rejoiced at harvest time,
when grain and wine abound.Ps 4:7, Sing Psalms 2003