I have grocery store client that uses a product called IT Retail. This program is written in Visual Basic and uses a SQL Server backend.

They have asked me to help them develop an on line store. I know everyone is doing this but so far I have never been part of developing an on line store. I have some ASP experience, but mostly I know VFP. I have some questions:

1) Does the client need to host their own website or can a local service provider do this for them?
2) I understand that having the client host their own site is best, but are their practical approaches to using an off-site service provider?
3) Are there any good 3rd party on-line store packages that would save re-inventing the wheel?