The best literature to show that the early church taught the Real Presence and baptismal regeneration is the New Testament. Both Eastern (Greek and Syrian) and Western (Latin) Christians and church fathers did not depart from these two scriptural doctrines. Although they eventually developed some mistaken views with regard to both sacraments, they did not deny the Real Presence or baptismal regeneration. It was the various non-Lutheran churches of the Reformation (Reformed--both Calvinist and Arminian--and Anabaptists) who departed from the scriptural teaching on both doctrines.
A book that offers faithful treatment of New Testament teaching on both sacraments, with some reference to the fathers and teachers of the ancient church, is Johann Gerhard's "A Comprehensive Explanation of Holy Baptism and the Lord's Supper," translated by Rev. Elmer Hohle. Decatur, IL: The Johann Gerhard Institute, 1996.
The earliest of the Church Fathers that you might find useful on the subject of regeneration in Holy Baptism wrote in 160 AD. See Justin Martyr's "The First Apology" 1:61 found in "The Fathers of the Church," Volume 6, p 99. New York: Christian Heritage, Inc. 1948.