K, BigDog has basically said it all, and I will just add a few refinements gleaned from the experience I have gained over the last little bit with the Cub and over the last 20 years with a Massey and my friend - "Manual Labour"
Plow - Cub-193 Moldboard Plow. This is a good plow and will meet probably all of your garden need. The 189 is a bonus and not necessary. The 193 judging by the for sale ads and post seems to run in price depending on condition between $75 and $150.00 US which is fair.
Cultivators - the Cub-144 Cultivator is a real assest for truck garden work, which is the kind of garden I have - you know, beans, peas, corn, carrots, potatoes and your other staples. (Tomatoes and Cukes are in another garden). Make sure that you get the moldboard for hilling or the disks - I prefer the moldboard myself as they are more traditional and work really well. I have the spring teeth version and they work very well in our mixed soils here in NB. I would also recommend that not only make sure you have 3 spring teeth per tool bar in the rear, but that you also have 3 spring teeth for the front tool bar. I only have 1 and am now looking for 2 more pairs so I can be a little more flexible when cultivating.
I would also recommend a set of plant guards if you can find them. They are very useful although not necessary. In my case they are because for some reason, as I cultivate, some of the younger plants get covered - which does not endear me to Emilie to say the least - so it is important that I have a set
Now for what I consider one of the more important tools - which I do not have yet but everyone should have if they are doing a garden. This is the disk harrow. I have a spring harrow - works nice, but still leave clumps after even many passes in a chess board pattern. The disk harrow is much better, whether it be an old horse drawn pull behind, a fast hitch version or the Cub-38 lift type. With a disc harrow, you do not need a tiller! When done properly the disc harrow leaves a well cut/no clumps and airy soil that is wonderful to work with, hills easy and provides sufficient air and water to young plants starting to grow.
One other nice to have is a "horse hoe". I don't know what it is called elsewhere, but that is what it is called here. It is basically a dual moldboard plow that is used primarily for hilling. It is used to make the initial hills for planting and then used after cultivating to inhibit weed and grass growth where none is wanted. The moldboards on the 144 can do most of this, but it is not ideal. Keep looking in the plans section as that is one of my must do projects before planting time this year.
Hope this helps, sorry for being wordy, but hey Dats Me