Depends on what you are going to store in each one. Typically 2 drwr is for pots and pans and would be one of the wider bases.

I've planned in a 4 drawer, 18" base.

What's a good option for the 15"? It is next to the stove.

If I had 15" next to the stove, I'd put in (actually, I did put in) a condiment pull-out, like this:

Do wall ovens radiate sufficient heat on the sides to degrade or damage ingredients stored adjacent to them? I was planning to do a pull out, just like this, for cooking spice and other ingredients. Though, I was concerned about heat.

thx!
:D

front - it really depends on what you need to store. I can't suggest highly enough that you take an inventory of what you have and begin to lay out where those things would be best stored. From there, you can begin to determine your best layout for the drawers. We have no way of knowing from your description where those stacks are other than the 15" one, nor do we know what you keep and need to store. Personally, if I had a 15" by a range, I would probably store hot pads, a trivet or two, often used cooking utensils and some spices. Since most of those things are rather flat, probably a 4-drawer stack would work well.

I ended up putting mostly tupperware in my 15" drawer base next to the range. Also pot holders and some spices.

I originally planned on this being my baking supply drawer stack but it just didn't seem to work. Actually it is for the best as it keeps the flour and such away from the heat.