Preface, I converted a Grizzly Lathe/Mill combo to CNC and really enjoy using it, though the mill portion really leaves me wanting.

I want a proper mill to do prototype and small production runs of parts. No more than a couple dozen of any one part.

I started looking at the G0704 but I think I will run out of size capability and get frustrated. The RF-45 has a bit more travel and definitely more rigidity. I can convert one, enclosure, coolant etc... or could look at a cheaper older VMC.

I know with the VMC I might get better quality of the original build, but will be dealing with an old machine that needs maintenance not to mention the conversion itself which could easily add a few thousand more.

I'm thinking something like this, it has similar travel:

Okada VM500 CNC Vertical Machining Center Mill Fanuc Rigid Gearbox Spindle VMC | eBay

Boston Digital BD22 1 VMC | eBay

Can anyone provide some strong opinions why I might have a better experience with one or the other? Is the quality of the average RF-45 decent enough to compare to a bigger machine? By custom converting it, maybe I get a package more suited to my uses? Or will I run into headaches when I try to mill larger parts or small production runs?

Thanks,
Carl