there is many types of support to be used for counter top for long lasting work... as ... 1) brick wall which takes 2" , 4" or 6" thickness space which is not good for below space as we will waste space for storage under counter... this is used where heavy material is used on top of counter for cutting any food items... 2) marble support... which will take 35mm thk space double support... 3) furniture base if the kitchen working person is using the sink properly for washing purpose and the gaps between the sink and counter top has to be sealed properly for leakage free to avoid any damages for below storage, as i will not prefer this in other area... this can be used only in foreign countries...

quartz is a man made product using natural stone and a resin material. No sealing and is stain proof. I have had my granite for 10 years. I have never had a staining issue and set hot pots down on it seldom, but it has never bothered it. I've sealed it maybe 2-3 times over 10 years. granite really doesn't stain. So, compared to quartz, they are very similar. It all comes down to what you like the best.

Granite is a material that requires very little attention when it comes to maintenance. However, with the Indian style of cooking, lighter shades of Granite often tends to show stains and go dull with time. What to avoid A neutral pH-balanced (i.e. non-acidic) cleaner is best for granite, and any natural cleaners with acids or with caustic nature like ammonia and bleach should be avoided. This includes vinegar, lemon juice, hydrogen peroxide, and citrus cleaners. Here's how you can clean granite countertops Wipe up liquids and spills of acidic ingredients promptly using a little to a soft cloth or a sponge and clear warm water. Some stains can also be lifted with a paste of baking soda and water. And to disinfect, pour one part water and one part 91% isopropyl alcohol into a spray bottle to spray and clean.

Madam Your options are ok.... From dimensions point, few things to take care: Your Existing platform depth, you need minimum 21 inches depth for Modular one... New Hood/hob will need 60*60 cm space.... From there you can finalize your sink position/size.... Sink size usually are from 380mm to 600mm, check your window size first!! Since you are removing the old door, plan wall shelves parellel to base cabinets (below existing countertop) Wire basket's are usually from 300 mm to 600 mm size, , based on your lengths it can be further discussed... On the other side there is an RCC shelves which you may have to remove for proper look......