Hello, my school has created a sumo bot competition of which it is compulsory for us to compete in as part of our course toward our final grades. the main reason this is part of our course is because this is my teachers hobby and he did this as a project in university so i would be very happy if i am able to beat him. 
the sumo category we are using is mega which means the max weight for my bot is 3kg and max size dimensions are 20cm x 20cm.
we have been told that we have to use Arduino Uno as our microcontroller and the l298N motor controller for our motors with no limit on component choice outside of this.
i have an understanding of the coding and how i will actually put all the components together but being a school student means i do not have lots of funds to create a good robot so this is my parts list so far, but i really would like some advice on motor and/or gearing to ensure decent speed but also pushing power. i also would be extremely grateful for any additional advice on my other components and where i can improve my robots capabilities.
parts list including the supplied microcontroller and motor controller and a couple choices of sensors.
https://www.amazon.co.uk/cart?ref_=ewc_gtc
this is my current design that i will be making out of clear acrylic sheet and metal corner support brackets. feel free to give any changes or upgrades i should consider doing.
many thanks.