Here's a piece of advice based on experience, look at the resident/non-resident rules for the first tax year (April 6 2017-April 5 2018) and make sure your wife will meet the non-res (< 46 days in UK during the tax year) criteria. My husband moved in the prior tax year and if you're not clearly res or non-res based on number of days in UK it gets really complicated and time consuming trying to determine status! We had a couple of vacation trips to UK prior to the move, and this ended up with my husband being in the UK for 53 days in the tax year. So now we are condemned to calculating where he worked, and how many hours, for the entire year, in order to determine his status! Not easy when he worked in US, UK, Switzerland, Canada and Germany!
Julia