SpeakingofSpeech.com: This site offers general calendars and parent letters for academic and summer months. Calendars appear to be posted by various SLPs. I would advise that you preview each entry in order to ensure that it meets your “approval” for best practice.
Thematic Units Calendar from SpeechTherapyGames.com: offers a week-by-week calendar for suggested themes or activity focus (appropriate for early childhood or elementary school students)
A Year of Thematic Units in Therapy from SpeechTherapyGames.com: fully customizable