Did you try
www.easy-forex.com?
Their Affiliate program was a sponsor here for a few months and they gave away some cash a few days ago to their contest winner.
I tried their platfrom and i found it very easy (as the name says).
Best things about it is that they don't charge you up the ass for deposits, withdrawls etc. You can deposit with a credit card and paypal and they don't require a shitload of documents to open an account for you.
I also have an account with RefcoFX but i cant use the money because they went bust.
As for marketiva ... they are a joke ... they are not even regulated and if you look at their website they dont even have a phone number where you can reach them or even an address where they have an office.