I Have About $10,000 To Invest, Should I Trade Only In Stocks To Begin With, Or Should I Try Futures Trading?

In futures trading the only contract I think I can trade will be the corn mini, because it has a small contract size (1000 bushels * $5=$5000), but it’s not very liquid. What other liquid contracts can I trade which have a contract size between $5000 and $10,000?
In stocks which broker do u recommend, etrade or optionxpress? Will they allow me to trade on margin both going long and short?
Also, where do u get ur data from? esignal seems to have eod package for $295, but I don’t know whether it is metastock compatiable?