Here are some other terms that may also be included: Confidentiality » the agreement and any information learned will remain confidential. Covenants » things each party must do while negotiations are taking place. Special Terms » any special terms that the parties agree will be in the purchase agreement, such as leaving certain items of furniture or hiring certain employees.
As with any professional correspondence, you don't want to seem too stiff or formal, like you're writing a letter from a Victorian template or a bad spam email asking someone to send money to a deposed prince overseas—but you also don't want to be too conversational. You're not in a dialogue yet, so it's important to treat this like a professional first interaction, and not like you're skipping several steps and asking to meet for coffee. The tone you're reaching for is, "You don't know me yet, but I'm interested in your company and want to tell you more about why."