Some of us are not particularly gifted when it comes to the quilting. I'm one of them, the piecing and planning is what I love. Can't draw to save my life. Just do not think in the 3D options of quilting. Plus, I'm just not a fan of the current style of dense quilting, I prefer a puffier batt and less quilting. My skills are getting adequate, with access to a long arm I can do quite a bit once we get the design challenge out of the way. Unfortunately, I don't have access to a long arm right now and I'm learning what to do with modern deep throat machine instead of my little old vintage Remington.
I'd keep it simple, especially with the throat size of your machine. I like the furrows idea of straight rows but I would probably alternate them, going horizontal with the tractors in one row and then vertical the other set of columns. I'd keep the thread white/matching the top including in the borders.
Even with my trusty old vintage machine I could do fancier stuff on the borders. I have vision issues and often draw my designs on parchment (not freezer) paper (dollar store carries 1x25' rolls) and then quilt through the paper which is held in place by strategically placed safety pins. Yes, you have to peel off the designs but to get a fancy border from someone who can't draw or see well, it can be pretty impressive!
Being drawing challenged I will sometimes buy pantographs. The parchment paper can be used to trace over them, in fact later today I'll be preparing the borders for my next quilting project this way. Pantographs and prepared paper patterns give me consistency that I lack, as well as show me what someone else considers a reasonable amount of quilting (which does depend on your batting).
I did a search on "farm quilting pantograph" and got some cool options.