Choice of cell lines depends on endpoints you wish to look at, but I understood that your interest is in the use of normal cells.
Various primary normal human fibroblast cell lines are commercially available and easy to handle. Examples are AG01522 and WI-38. Its hTERT immortalized cell lines with prolonged lifespan are also available.
For primary normal human epithelial cells are more difficult to handle because of the cost for the culture medium and short replicative lifespan, but again, its hTERT immortalized cell lines with prolonged lifespan are also available.