Should I apply for The First Year Choice (and Joint Return Election)?

I'm trying to work out if it is better to apply for the First Year Choice (to file as a resident alien, jointly with my wife) or not (and file as non-resident aliens, separately).

Details:

  • My wife and I moved to the US in August 2017. 
  • In the UK, I earned c.$100,000 p.a., or c.$60,000 for the first 7 months of the tax year.
  • My wife earned c.$10,000 over the first 7 months.
  • On moving to the US, I still earn c.$100,000 p.a., or c. $42,000 for the last 5 months.
  • My wife hasn't yet worked in the US
  • I rent out my property in the UK, at c.$17,550 for the whole tax year.
  • I will qualify as a resident alien in 2018 due to the Substantial Presence Test

As a non-resident alien, I don't have to pay tax on my UK income, although I know the US has a tax treaty with the UK. As a resident alien, I do have to pay tax on UK income, but I can claim more with-holding tax (such as spouse) than as a non-resident alien - I just can't work out if I will end up paying more tax by making the First Year Choice or not.

Any ideas or suggestions how I can work this out welcomed!!!

Thank you,

James.