Have you gone to look at soapstone? There are many different varieties and some have some veining that may clash with marble. Have you looked at marble to know which one you are considering? The veining makes a big difference.
Hope that helps.

The slabs that they have here do have veining that I thought clashed...I didn't know if it jwas just me it bothered.
So, soapstone & butcherblock
or
absolute black & marble

Read up on absolute black, especially honed absolute black. Many people are dismayed by keeping-it-looking-nice issues. Same advice on marble-check out what people say as far as upkeep goes to be sure you're OK with that. If marble turns out to be too fussy for you, maybe you'd like Cambria's Torquay?

I'm not saying you should rule out the AB or the marble, just making sure you know they each have issues which may or may not be issues for you. Whether you do soapstone/butcher block or AB/marble it will be fabulous because all of those are great looking.

Have you thought about using the same on both? I am just throwing that out there since you are still choosing...my designer told me that if I wanted two different c-top materials...I should keep my island the same as my perimeter cabinets. Now, this is just her opinion, so take it with a grain of salt. She said there would be too much different stuff going on. I listened to her, and for my kitchen, I think she was right. Anyway, just wanted to throw that out there! I like ALL of your c-top options...love marble the best!

You need to play with samples here before having any "finalists" on look alone. Decide what you can live with and use.

What do you plan to do with the backsplash? Maybe a marble backsplash, which is supposed to be less maintenance...honed abolute black granite on the countertops and butcher block on the island?

Marble is also pretty as a countertop, so it depends on what you want to use (function wise) and how you want it to look. Some ideas :) {{!gwi}}From Kitchen plans
{{!gwi}}From Kitchen plans
{{!gwi}}From French Country Kitchen

Not black, but a dark wood island... {{!gwi}}From French Country Kitchen

And 2LittleFishies inspiration kitchen... {{!gwi}}From Kitchen plans

Keep in mind that both soapstone and marble are "large patterns" and could very well clash. Don't just look at the colours but also the size of patterns in the countertops that you are considering.

This is just my 2c worth but I agree that if I had two different finishes on the cabinets I would probably go with the same counter top all around UNLESS it was wood. If the island is going to be not only a different colour but also a different style so that it is going to look like a piece of furniture then I think you could put wood on it and something different on the perimeter. Keep in mind though that wood also, depending on if you make it butcher block or wood strips that there is also a pattern there.

Ok, so ya'll think it would be best to do the same stone on the perimeter and island OR do a stone and a wood island.
I'm scared the marble will look too formal (we are doing an open colonial-type house) for our living. It is sooo pretty though.
The soapstones they have are classic which has a dark green tint or something else that I can't remember... It is more charcoal I believe. Several of their soapstone slabs had a rust/brown tint. I don't think I want a rust/brown tint.

Okay I am going to toss in another idea that might work,
Honed Jet Mist. It is not as black as AB but it does
not have the issue AB does. (finger marks, water drop marks)

And everyone knows I love Marble.
Here are some images that might give you ideas of your
own space.

~boxer

The images below are Marble on the Island
(not black cabinets but dark wood) and granite on the perimeter white cabinets

Granite on the island might be pretty too!

Black granite on island and perimeter no marble :(

Marble on both island and perimeter

Soapstone on island and I think white marble on perimeter

Soapstone on both perimeter and island

Notice that in almost all of the above photos that even though the perimeter cabinets were white and the island was dark and there were two different countertops that the island countertop had a white/off white background to tie in with the perimeter cabinets. There is, in all of the pics a tie-in between the island and the perimeter of some sort.

I find most stones don't mix well with other stones, unless one is extremely "calm". There are some that work together, but it is a harder look to pull off.
Since your island is already a different color, I'd prefer one countertop throughout. If you integrate some butcherblock into the island top, that may give you the best of both worlds....

Thanks boxerpups for the pictures and the jet mist is beautiful. I might have to make another trip to the stone yard. Decisions, decisions...