Visually think the black looks chunkier than the stainless one which also has the advantage of having controls at front. Very hard decision to make, if your all white kitchen is having noticeable stainless steel handles may be go with stainless steel top.

Charcoal will give you more scope to mix in other items around the pool and is much more modern.

Both look like nice designs! If you like this style you should check out what Zanda Architectural Hardware has on offer - they've got a great range of modern door handles.

I like both ideas, however think it's good to consider the practical as well as the aesthetic you are wanting. Consider your space and picture how each would look in the space you have. To throw a few more ideas at you, here are a few pics I just found on Houzz. There are certainly some very cool designs happening in the architectural world. Just decide what moves YOU and to heck with what a builder thinks-it's not his house (even if he is a relative). :)