I'd like to create a Form where a web visitor can enter personal information where I can retreive it and process it securely. After reading about Secure Mail Forms, I'm wondering if it would be more secure to create an upload Form, rather than emailing information. I look forward to replies/opinions. Thanks.

SSL certificate and a form on a HTTPS page it's nothing different to a form on a HTTP page.

Depending on the type of data you are collecting and where you are based, you may also need to demonstrate the data is secure and be compliant with all relevant data protection acts nad statutes.