enzo, she said she wanted to leave the mac clear of windows, i.e. no dual booting, hence she's looking for a PC.
deltadevil is right though we need a lot more info, i'd imagine 2 honking great big screens, good connection, can't imagine that the CPU does a fat lot though for a 'from home' forex trader.
Good quad core (always have a core free for that killer trade
) and a decent amount fo RAM should work, what does the software you are using recommend.