From my analysis and according to my observations Forex-Metal is better than you cause it has nice facilities for traders like
35% first deposit bonus;
free automatic trading signals
ECN accounts with low spreads
Leverage up to 1:500. .
Rebates for active traders starting from 0.5 pip
They now have convenient local deposit options in Nigeria, customers can ad funds to trading accounts via local bank in Naira, USD or EUR.
$100 "no deposit" bonus.
Beside all of these it is a regulated broker so there is no need to fear