[Typo3-shop] Advice on Planning

[Matthew Manderson]

Regards

The time has come to plan my first shopping / products feature for a large
flower delivery website.

Does anyone have experience to advise the best approach to take and ideally
compatible with RealURL?

Options seem to include:
1)Using stand alone software like OScommerce 
2)Using tt_products
3)Holding out for Ext_commerce 

If anyone has some similar live examples of these I would like to have a
look?

What idea of time will I need to budget to implement this type of feature?

Thanks a lot for any help.

Matthew