I read that ketoconazole might cause gynecomastia... is this regarding the pills or will shampoo cause this too?

Unlikely: Toxnet reports that gynecomastia may occur with oral ketaconazole but will go away in some patients after they stop the medicine. Adverse effects reported in patients receiving topical ketoconazole 1 or 2% as a shampoo to the scalp include increased hair loss, irritation, abnormal hair texture, scalp pustules, dry skin, pruritus, and oiliness or dryness of the hair and scalp.