Need some expert opinion: what plugin to start with

I've been studying and preparing for MySQL database to build a shopping site.
But I'm lost and don't know which way to turn.

My site will;
- not need for user name and password, but at the end of the order, a customer will type in their info (name, address, email etc...).
- not need for payment gateway (payment will be done by bank transfer)
So the site will be like a online enquiry form with product order function.

The purpose of this is;
- I am located in Japan, trying to sell some rare sports good to Europe/America.
- 90% of time, customers need to consult us to define the most suitable products for them. (this is why we don't want to take credit card, since return of goods/refund could be happening a lot.)

At the moment orders are made by phone calls or email (customers write down the products they're interested).

So far I have created ;
-web layout (hand coded dreamweaver template)
-MySQL tables (for ProductCategories, Products, OptionGroups, Options, ProductOptions)

I have so far studied MySQL database, read how-to pdfs of DetaAssist and eCart.
These plugins have functions that I don't need, although it seems possible to modify to what I want.
But I don't want to make a wrong start.

So could anyone give me some input?
Thank you,
Rika