What do you mean 'which models have Internet"?
They all have Internet access via the BB data plan. If you plan on using any of the BB related services such as email, BBM. AppWorld, the BB browser, etc., then you must have the BB data plan
If you mean which have WiFi, then that is a different issue. BlackBerry - Wifi PDA - Wi-Fi Enabled BlackBerry Smartphones - Wireless Networking
You are limited in what you can do with just WiFi however.
And please update your profile to show which BB you actually are using.