4X8 olfa, 4X16 for piecing, an O'Lipfa (edge lip) ruler that is 4X36 for large pieces of fabric and binding strips. I also use the rolling ruler by Fiskars but it no longer availbe in US.
With the last rule it is push down the palm piece then forward, safe for kids and adults, no blade exposure. It has this thin soft rubber that keeps the ruler from slipping as well.
The other ruler I use the most is the Olipfa 6X24. Olipfa is made for Olfa and designed by them as well. They have ridges on the bottom to stop slippage.
Quilt expos are a good place to find all in one place but isn't the cheapest way to go. Internet saves a lot of driving. Good Luck sounds like a full schedule.