(You can use your pre-existing MT4 account if you like.)
Or you can open a brand new account at one of these forex dealers or brokers:
Oanda (I like their spreads)
FXCM (I have used them in the past)
MAKE SURE THAT YOU OPEN A "METATRADER 4" ACCOUNT. This is a type of trading software that you will never need to download - but that TYPE of account lets us link up and copy trades to you.
I cannot and do not endorse or recommend any particular fx dealer or broker. I do not work for a broker or fx dealer. I work for you. Open an account where YOU want to open an account.
Some dealers or introducing brokers will offer rebates on every trade you place - if you open an account with one of these fx dealers or brokers, it could make the trade copy software free.
There are possibly other FX Dealers in the U.S. that can handle the trade copy service. If you do not see YOUR favorite dealer on the list, PLEASE do NOT email me about it. Just call your broker and ask if they have MT4, and if they do, then you're good to go.