Quote from $preader:
You might want to look into the visa situation too,if you and your wife are both American your passports will only allow you to stay in the UK for 3 months,that's the visa waiver that exists between the countries.
You can apply for a 6 month visa at the Embassy but they will want to know why you are going,what you're going to live on etc etc
If you want to stay any longer it gets a WHOLE lot more complicated.You'd probably be alright for a little while leaving for 2 weeks then coming back but they're not stupid and you don't want to get flagged,especially if you've paid for rent and aren't allowed back in,even to get your stuff.
Also as a non-resident a landlord won't be able to do the background checks like they can here but if you pay a big chunk of the rent up-front and a hefty security deposit you could by-pass it.