chanj: Buy a package of jigsaw blades with a selection of general, wood, and plastic. Install one and see how well it cuts through the plastic laminate and substrate by just starting in 1/8" or so. You want to avoid chipping. Your backsplash may not let you get the jigsaw close enough to cut the rear. If not, and you've got the room, just make the front cut larger and move the sink forward. It that's not an option, you could use a laminate trimmer with a straight cutter freehand, or a Rotozip to cut the rear.

Shut off valves should always be replaced. They often get stuck open because no one ever exercises them. And they leak when someone does try to use them.

Andy: "Here you go." above is a link to the sink you should use. I've done your exact job at least 5 times. The corner reveals may not match perfectly, but that's a small price to pay for a single bowl sink.

It's really hard to quantify, as the workflow looks so different now. And I probably also use the kitchen more intensively, now that it is so much more efficient to use. It's not all thanks to the workstation sink. But that plays a really big factor. A lot of our design decisions were made after we decided on the sink. If I had to make a guess, it saves maybe 5 minutes every morning, when I am preparing breakfast and take-out lunch for the kids. And it saves 10 minutes for your average weekday dinner. But there are big error bars on these estimates. And the numbers don't do it full justice, because it doesn't reflect just how much less stressful it as to get food ready while the kids are hovering all around me. Having a central workstation where I can do all my prep and clean up in one go goes a long way towards cooking and cleaning up efficiently. I usually serve the food to the family and then go back to the kitchen to quickly clean up before joining everybody for their dinner. Most days, it takes me about a minute to have the kitchen back in presentable shape. Me or my wife will clean more in-depth after the meal. But it's nice that the bulk of the clutter and waste can be put away so quickly. Also, the integrated drain board gets used extensively in this family. It's a huge time saver that I can set things out there and have them accumulate a little bit before I need to dry them and/or put them away.