Please help- I am new and couldn't find these issues addressed anywhere else. Is this a cross sell kind of thing?

1. Is there some sort of module/add on where I can have certain options displayed to my customers at checkout, depending on what they have purchased?

I know I can add another product category but that isn't what I am looking for. Let me explain.

We sell fingerboards. If they buy a fingerboard and wheels, for example, I want to display AT CHECKOUT ONLY the option for me to assemble the wheels for them for a set cost.

So, do I have to set these 'add on services' as products?

2. I would also like to add on an Express Shipping option. We ship free worldwide, but if they want us to Overnight or use Priority Mail - is there an add on for that to show, ONLY at checkout? do I have to enter weights for everything if I do that?

3. What about upgrade cross sells for products? If they buy a board with wheels, can I recommend at checkout that they try our bearing wheels for just $12 more (example) or the super bearing wheels for just $20 more? How would I do this?

Any help would be greatly appreciated!
cherie

www.prowoodfingerboards.com/store