Costumize the cut-off and product page

The website it is a Gourmet Online Grocery and it was Built on Shopify, some features are important to be in a way that costumer have easy access. The part which need to be redesigned it is at the product selector no matter if the product it is in the list with the other products or it is a page opened with the specific product, the client should be able to select the wight or quantity just from one click. For example: The product it is tomatoes 1Kg for 10$, but i want to offer the option of adding to cart 200Gm, 500Gm, 800gm etc, and once they selected the weight, automatically to calculate the amount. There should be a button with dropdown or dropup. If we speak about an item which the order it is per piece, then the client should be able to select 1,2,3,5,7 etc items that will be automatically calculate the amount. There should be also the possibility to add Watermarks for the products for example Round Green tag with Organic written on it, or New Stock, or Local Produce. Regarding the cut-off should be like this: We delivery products to many cities but some of them we have same day delivery and some of them we have 1 or 2 times delivery per week. When the client make the order, at the check out should be able to select the date and time for the delivery which will show him the available slots according to: City with same day delivery: If they order before 1pm they will be able to choose delivery time between 2pm and 8pm ( not to show the slots for the same day before 2pm like, to only show the next delivery timing. If they order after 2pm they will be able to choose the delivery next day in the morning between 9am and 1pm or 2pm to 8pm. Cities with 1-2 days delivery per week: Lets say Sunday and Thursday: If the delivery it is made Saturday before 6pm they will be able to select the next delivery which in our case it is Sunday or they can choose for Thursday. If they order after Saturday after 6pm, or Monday, Tuesday, or Wednesday before 6pm will be able to select next delivery day which will be Thursday. For all the orders no mater the city, there should be a minimum amount spend to be able to receive free deliver, other wise, automatically will show at the check out a delivery fee according to their area. Also it can be costumized to have an express delivery for a certain fee. All those rules and cut off should be automatically calculated according to the city. To be easier, i guess should be connected with google maps or to work by Tag of the city. Once typed Dubai, to show the rules for Dubai. Thank you for your time and hope to find someone who can do it proper and in time.