If you create a parts wants list, Bricklink has an search algorithm that recommends a mix of stores that will best get you want. However this won't take into consideration postage and handling or minimum order quantities as those are not a measurable parameters in the Bricklink database. This is why I presumed you were not satisfied with your bricklink experience.
The_Black_Sheep's point is a good one and may help you get started. Though at the end of the day if your have a fixed design it doesn't change the fact that the bricks you need are the bricks you need though it might make you consider substitution of some of the less readily available parts in your design.