One thing to consider is "milling around space." We have 5' between our main sink and dishwasher leg and an island. Altogether this space has about 12' x 5' of open area for people to move around. From prior experience we know that with clearing dirty dishes, putting away food, loading the dishwasher, washing big pots and pans, drying the big pots and pans and then handing them off to be put away that this is going to be Grand Central Station in our house. Try to visualize how you work day to day and also on special occasions and holidays. If you could post a layout it might help someone else to answer if 7' is too much space for you. However, try to work through mentally how people will be moving in this area based on your own family and that may give you the answer.

48" is plenty, but it depends on how much space you have on the other side of the island. In our case, the kitchen is open into the rest of the great room, so we decided to push the island out to 60" (5 feet.) This allows the 2 of us to easily cook or work in the kitchen without bumping into each other. You will need to take into account the placement of your primary work areas, as well as your cooking style/work pattern. How often do you go back and forth from the main sink? Is the island used for prep/cooking, or do you do most of that in the wall units? In our case, we use the island about 75% of the time for prep. I even put a baking center at one end, with everything from flour to mixing bowls and utensils in drawers so you don't have to walk all over the place. One thing which helped was to mock out the distance on the floor with masking tape so I could see and feel how it felt. I'm pretty tall with long legs so I appreciate the extra distance, you may not.

I love Lamps Plus. Lighting Universe, Restoration hardware, Vintage Lighting, West Elm (stop me) are all great. I don't know if it'll work for you, but have you noticed those screw-in things that you put in canned lights to create pendants? If your lighting is in the right place, these might work for you?

"The moving of the sink on the right-hand picture, is this to allow more food prep space?" Yes, and to allow you to prep in front of the window. Any way you lay out the kitchen, you're going to have a traffic path through the middle, except for a U, which takes most of the dining area. You need to think about how you enter, how guests enter, and how you want to use the kitchen. Here's another plan with a nice prep space, with the appliances arranged more like cpartist suggested, but it keeps the peninsula across the room, and preserves the dining area. You'd have your back to the long hall and front entry--that's probably really bad Feng Shui, but if you'd prefer the sink under the window, then it's a good plan. What size fridge and sink are you planning to use? If you have 118" available on the top wall, and subtract 24" for the cabinet on the right, 30" for a sink, 30" for the fridge, 24" + 2" for the DW and return panel, plus a couple of inches of filler beside the sink cab, that leaves 6" for the pull-out/filler beside the fridge. If the fridge will be enclosed, subtract another 2-3". I don't know if that would be enough to allow the fridge door to open far enough to remove the crisper for cleaning.