Forum Moderators: buckworks
If you want sell online you would do better to stick to a tried and tested shopping cart layout, like OSCommerce for example. If you try to get too fancy or confuse people they will just leave and buy elsewhere. Remember that you want them on your site to buy your products, not to admire the graphics.
They must be able to find what they are looking for intuitively through correct categorisation, etc. I believe that the basic OSCommerce is as good as it gets in this respect.
You might want to look into a flash solution for a really polished store.
What differences can I expect between a site built by a programmer and a customized solution, if I already have an artist?
I'm a little confused by the difference between "built by a programmer" and "customized solution," so for the sake of answering will assume the first is a scratch built ordering process and the second is one that if freely available you want to customize.
What you need to do is see if there is a solution out there that does everything you need functionally and put a programmer to tweaking it to suit your needs - creating the templates, configuring the cart.
Unless your programmer is well-versed in the pitfalls of developing shopping cart software, you may wind up investing a great deal in developing an ordering process from scratch and have something that may have a lot of bugs or fall short functionally. A good programmer, however, can build it precisely to your needs, so it's a matter of time and budget (as usual.)
What you need to do is present your artist's designs to a programmer and begin seeing if the design will integrate into the ordering process. A good rule of thumb to develop by: form follows function, too often it's approached the other way around.