It seems that 49" is a standard size for vanity tops. Have you already confirmed that you can't use a standard size -- if not that one then the next size down, 36"? You can get ready made stone ones in this size, with built-in sinks if you like, on ebay and in other places. Also, here's an auction where they want to get rid of a top and will cut it down for you. Where there's a will there's a way! If you really want stone you can get it for less. Kashmi mentioned checking on fabricators in your area. I found one fairly close to me who makes lots of vanities and can do it for far less using popular stones that they stock -- you don't pick your slab. If you can use standard cuts for length and number of holes you get an even better price. I had formica in my last house, and amazingly enough I never ruined it with cleaning products or nail polish. I was always afraid that I would hurt it, though. Here is a link that might be useful: ebay -- will cut down to your size

When you look through the pics in the linked ideabook, you'll figure out quickly that my rec is to go very dark w/the cabinets. My new bath will be primarily light counters, light shower tiles w/some kind of accent (probably sticking w/a greyish), and my cabinetry will be deep brown/espresso, like my kitchen cabs. All the woodwork in the bath will be dark (baseboards, door and window trim, panelled soffits), and I think it will be great w/marble counters, maybe a light grey glass tile in shower w/pieces of marble for accent. I do want to bring in a color in the backsplash and use it in shower - maybe a light blue? HOWEVER, the minute I read your post, all I could see was the dove grey cabinetry I've been seeing and have fallen in love with! I'm going to do all grey painted built-in shelving in my library (which is a big step for me, my last house had no painted woodwork, not even any stain - just the natural colors of the mixed varieties of wood I used.) I totally get what you're picturing about a beachy feel, coming in from your bedroom. My only concern is I've seen several baths lately that mixed taupe/sandcolored tiles on floor and in shower then used blue glass tiles for accents, and they just looked kind of "off" together. It didn't feel like the styles were headed the same way. That's what I'm afraid would happen w/taupe cabinets. Of course, some of that would depend on the style of the cabinets themselves. I hope the pics I found on houzz.com will help - I've added comments to a couple of them to explain why I thought they might be inspirational. Good luck! Here is a link that might be useful: houzz.com ideabook w/possible cabinet colors

Trapped between porcelain carrara-look alike bathroom floor tile and beautiful grey-blue real carrara bricks wrapped in thassos mosaic on the back wall of the shower, surrounded by white subway - searching for the perfect vanity top and shower threshold. Afraid that another carrara will be too busy (impossible to match either floor or mosaic - current carrara slabs in our area are too choppy), so looking for white marble - thassos would have been perfect but has anyone seen it 1 1/4" thick? Only 3/4" in our area, afraid it would look "cheap" without ogee edge.... Look alike options?

you need a right offset. you like this one? comes w/everything (except faucet I think_. Overstock https://willowbathandvanity.com/product/36-x-22-willow-collections-aberdeen-right-sink-bathroom-vanity-in-hale-navy-bluey-with-2-in-calacatta-quartz/ this place also has it for less money^ white too I'd find a vintage wood chest and modify it to accept the plumbing. find a mcm wood chest, or dresser, (you could paint it if you want, any color) or leave it as wood. or, just get a right off-set sink (meaning sink on the right side) . I did one here w/this bathroom. the vanity is 36" with a quartz countertop. Do a wall mount faucet for more counter space and easier clean up. there are a ton of 36" right offset vanities out there. A lot of them come w/countertop and sink. you can do wood, or any color Gray? they have plenty of others here https://www.build.com/product/summary/1446977