How promote webiste for USA and UK visitors?

craigslist(US)
gumtree (UK)

You can try US and UK directory submission sites. Good Luck

dont think there is need for 2 websites. One site would suffice. In google webmaster, do not select any geograpgical location but ensure you dont select ‘unlisted’.
Get quality back links from top sites in both UK and USA. Use good directories for submission; article marketing etc

adbrite of course can target visitors… try also youtube…

Use business and finance related social media as well as forums, i have seen many niche sites in your business area which can help you lot in traffic as well as keyword rankings

worth to try

u try which country that u want to target in http://www.google.com/webmasters/

Advertise with sites that have high USA and UK traffic. You can take a look at their Alexa ranking and view details of where their traffic primarily comes from. You are in luck for press releases because there are a lot of US and UK companies that you can distribute your press releases to for free.