Unfortunately, no matter what type of system you choose to implement, as a small-business owner, you'll probably be more at risk for security problems than larger companies.
"Small businesses are probably at greater risk because they don't have an in-house staff monitoring the security of their system, and entropy sets in," says William C. Boni, leader of PricewaterhouseCoopers' Information Protection Practice and co-author of I-Way Robbery: Crime on the Internet (Butterworth-Heinemann). "If you don't maintain a consistent degree of readiness, [Internet security measures] actually become ineffective over a period of time."
While getting involved in the world of e-commerce is almost a necessity these days, remember the security risk is great--and it's only going to intensify in the future. Luckily, firewall costs are now coming down, according to Tippett, and ISPs are improving their security setups. So there's help on the horizon.