Hi Ryan and welcome aboard.
We cnc the 45 mill with the geared head and square column. There is much I would do differently second time around.
The question you need to answer are
How accurate do I want to be 0.01mm or 0.0001mm.
How fast does it need to run. 500mm/minute or 8000mm / minute
What do I want to cut? plastic, aluminium, steel, harden steel
Answer these and then you can buy the right set up.
Your link shows a round column mill you should be looking a a square or dove tail column if you want to use the z axis
If you do get your mill from HF the first then before turn it on is to strip it down and find all the faults before using it.
I am now looking at building a new mill from scratch using modern gear not a design that has not change in nearly 100 years. Most probably will not work out any dearer then what I spent on my first cnc mill but many times better.
Arr just my thoughts
Do not now where you are but you (and any one else) are welcome to come and have a look at my set up.