if you want to have quick response speeds, especially during your trades etc, i'd suggest to use a pc not older than 2 years.
Where possible install linux/unix/freebsd, which would give you a much better response time over the same connection and keep the unwanted junk to a minimum.
If you...
Ofcourse there'd be a lot of IT systems. Try looking at the postings on monster or so. Also you might want to get in touch with some recruiters who'd have a better clue as to which company is recruiting now.