I love the 6x24 ruler and use it the most. I also use a handle on it to keep my hands away from the rotary cutter. You can get those at Harbor Freight. Most of my rulers are Omnigrid and like the contrast the yellow lines give.
I noticed the Hancock's has their quilt notions on sale- 40%. It might be a good time to look if there is a Hancock's close to you.