Are you talking about using either 2 cm or 3 cm slabs? I've never actually seen them measured in inches. Presuming that's what you mean, there are a lot of threads on that topic here. Type "2 cm vs 3 cm granite site:gardenweb.com" into your search engine and you'll turn some up. The bottom line is that you can use either for your islands. The 2 cm slabs are placed with a plywood underlayment and generally have another 2 cm strip of granite laminated onto the edge to give a nice edge finish and cover up the plywood. 3 cm slabs don't need an underlayment and have a nice fat edge for finishing built in. 2 cm slabs are more popular (i.e. more available) on the west coast and 3 cm more popular on the east coast, but that is not a universal comment on availability. I live on the west coast and I have 3 cm granite. Functionally you can go either way and be comfortable about your decision. When you're looking at costs, be sure to factor in the extra fabrication expense for the laminated edge and the extra expense of fabricating a stone that eats up the fabricator's saw blades like the really hard quartzites.

Our soapstone backsplash is 3/4". My DH cut it from left over stone from our counter install. We tried out the 1 1/4" to see if we liked it but it just seemed too thick. But ours is only 2" tall. Maybe a taller backsplash would look ok with the thicker stone. You might want to try out some scrap soapstone to see if you like it before committing to size. I have some pics in the link below. They don't show the side view but maybe they'll help you a bit. Here is a link that might be useful: 2

@houzzgirl01: Thank you for the kind comments! The island is 4 feet x 6.5 feet. @Russ and Ravencajun: Believe it or not, I got rid of the single beam! And had to add two new ones in!! The old beam was in the way of the row of upper cabinets. The new beams were needed to hang the pendants of. We used rough hewn cedar and stained it to somewhat match the floor. Thank you for commenting on them. I debated putting them in and in the end, had to because there was no other way for the pendants to be hung. @romy718 and the color of the cabinets is castle rock sheer from Yorktowne cabinetry line. @stir_fryi, unfortunately I haven't put anything in the 15" cabinets! But I'll take a picture of the inside soon! Thanks for the comments!

Hi yes - thank you for the response. Actually, ~50% of the cabinets are brand new custom cabinets. The whole reason I ordered the customs was so that I could get the spacing even, or at least somewhat even. I was told that going with all new semi-custom was not allowed. The Home Depot rep's exact words were "I can't let you do that, you have already paid the deposit". I said I didn't understand because the order hadn't been placed yet, he told me I could change my mind on anything before the order was placed and that I would buy them from Home Depot. He said "Sorry, Home Depot will penalize you a lot of money". But I could do some total customs because it was his dept (i.e. he gets commission). The installation manager told me during the install that they should have never accepted my job as a reface (there were a number of other complications). So I'm not sure what to do now.