Just to add. If you choose BA then you will also get miles and tier points for the flights.
If starting in AMS and paying £2000 each then the tier points and miles you would get would be as follows.
I have assumed all are silver card holders in the details below, if not then simply half the miles, the tier points stay the same.
Club world gets 560 tier points and 41212 BA miles.
First Class gets 800 tier points and 42490 BA Miles.
If you travel as a family of 4 and have a household account then you would gain 169960 miles, enough for a First class return redemption ticket to the USA.
If you get a BA Amex premium plus card to pay for the tickets add a further 24000 miles and once you have spent £10k you get an Amex 241 voucher. Meaning you miles will now get you 2 seats in First to the USA.