Tom emails Ciara to accept the offer of purchasing her offer of buying the house for 380,000. Tom and Ciara agree for a deposit of 200,000 to be paid and the balance of 180,000 to be paid in two months' time upon completion of roof repairs (in the house that tom is purchasing).

can someone explain what kind of payment is made by tom in this case and what kind of acceptance is an email for an offer with examples from some previous similar cases in law. also is there any consideration in this .