The Graham is a much better forge than the mini. If you are just wanting to start forging and will be doing smaller knives, it will work. You will eventually outgrow it, but you may do that regardless of what forge you buy. IF you like the Graham, I would buy a mini and order a Graham. When the Graham is ready (right now Charles is backed up until late 2019), you can probably sell the mini for 75% of what you paid.
The Majestic is a popular type of box forge. It has two big hot spots, but for general forging and damascus it will be fine. I don't know how good HT in it is. FIF certainly has made it popular, and they do HT in one. The Graham is a better forge that the Majestic, IMHO.
I use a three burner NC Whisper Lowbow most of the time, which is also a box forge. I have no problem with HT in it for simple carbon blades. It will do most any type forging.
When you outgrow whatever forge you buy, you will likely want to build your own and have exactly what you want. By then you will know a lot more about forges, too.