Regarding credit profiles...
1) Another easy option to get some "loan" action from Loqbox. Basically you take out a "loan" for an amount you choose like £400, but you actually never receive the funds. You then pay it off over 12 months and Loqbox updates your credit profiles just like you took out a loan and you are paying it off. At the end of the term, you either have them pay you back the entire amount minus £35 fee, or you open a bank account through Loqbox and the £35 is not taken from you.
Used it for 2 years when I first arrived and I feel it helped boost my profile somewhat.
2) When you arrive, grab a PAYG sim for you and wife from the airport or local supermarket (no RICA required here), I choose EE. Then after 2 months or so, the service provider will phone offering you a contract which you then take as they will then also update your credit profiles monthly.