You should be careful about setting up that account as thanks to FATCA, banks are now required to report accounts held by US citizens. I would strongly suggest getting caught up on your US taxes and FBAR's (if applicable) before doing anything further.
Fortunately it does sound as if the Streamlined program will be a good fit for you, and with that program you can file only the last three years of taxes (and six years of FBAR) and be considered back on track. Also, as the rates you have been paying in the UK are likely higher than what you would pay in the US, there is little chance of you owing the US anything. If you do not owe anything, you do not need to worry about fines or penalties for coming forward.
Lastly, I agree with Guya that you may need professional help to navigate the trust issues as they can get rather complicated.
Good luck!