One of the benefits of a homemade tool cart is that you have the freedom to design it to your need rather than searching for an existing cart and adjusting your needs to fit the cart. You can take a simple design and add drawers or sliding trays. You could leave out any compartments that would just add weight without serving a real purpose for your needs.
There are many types of building materials you can use to build your handmade tool cart, but the most common are metal or wood. There are various types of woods and metals available. Whether you decide to use a strong, durable option or something that is lightweight, the choice is yours when doing it yourself.
There are "greener" options available for those interested in using renewable resources. Consider remilled, salvage and recycled materials. Some of these wood supplies available are of better quality than what is offered for purchase.