Require Accountant to submit my UK property Tax Self Assessments as I live overseas

I am from the UK and live in China. I have been living in China full time for 5 years. I have been renting out two properties in the UK. Last year I sold one of them and we are looking to purchase another. I need an accountant or bookkeeper who understands the HMRC tax laws regarding property rentals and sales for UK landlords who permanently live overseas. Soon the short tax return will be due and then my self assessment declaring the rental income and also the property sale. As I am living overseas I believe that I will not have to pay Capital gains tax on the property that was sold last year. The property was sold in June 2015. The property that was sold had a sale price of 255,000 British pounds. The purchase price 6 years earlier was 178,000 British pounds. Regarding the rental income. There are only a handful of transactions per year. Rental income coming in and a handful of bills going out including letting agents fees. It is very simple however I need someone to do this for me on an ongoing basis. Please confirm: 1) Your previous experience submitting tax returns such as these for property lettings and sales 2) What approximately my tax liability for this sale will be and how you will process this for me. 3) If you will be able to submit my short tax return and annual self assessment to both “Companies House” and also HMRC for me each year 4) Your charges for doing so? 5) What you will require from me each year and when?