Portal - To Use or Not to USE ?

I have been trying to figure the "BEST WAY" to do the following:

when placing an ORDER in my system, Still in the design process to make sure i am not going to go in circles.

if user selects products i have the following relations>

products »» class_products »» class»attributes»products

so if products = char_suite,

suite was selected and the have to enter the following classes have to be entered :

class»»products : cake & cupcakes & stand

then they have to select from

class»attributes»products:

cake : flavor, filling,style, image

cupcakes: flavor(s), colors, topping

stand:(selection)= white | gold | silver

i am trying to figure most simple way ..

any help would be great...