I know you can setup products with options in Magento (1.9) with a configurable product it can be made up of different simple products so you have a Configurable product call widget and it made up of simple products call widget-blue, widget-red etc
But the problem is that the prices and stock is not taken from the simple products but manually entered which is not practical if you have 100s of products (as we update our skus prices and qtys with magmi). So I'm looking for an extension that let you configure a product from different simple products and it gets its price and stock from the simple product.
I had found mageworx's Magento Advanced Product Options extension but there support told me there extension does not work that way.
Are there any others you can recommend
I suggest you checking out this Dynamic Custom Options extension for Magento 2.
It helps to associate options to products and gets the price, stock information, sku or title after product updated. If a customer selects an option, the associated product inventory will be deducted.
Hope it will be of help!
You can try this Color Swatches Pro module for Magento 1 (also available for Magento 2).
This extension will let you automatically use prices of associated simple products when a certain option is chosen by a customer. Additionally, all other data (image, SKU, description, etc) can be reloaded for each option of a configurable product.