I already have a spindle from another machine. Specs seems similar to the Dewalt being sold in the kits. I’m fixing to place the order and would rather not buy another if I don’t have to.
I have a Makita 701 with a 65 mm mount and a Hitachi 12vc with a 80 mm mount. Basicly, anything that you are able to mount on the X carriage will be alright if you have the proper mounts. My makita mount is the same mount that is used for the DeWalt and the mount for my Hitachi is one I purchased from Zenbot.
I forgot to add that I have aftermarket Z axis’s from CNC4Newby which are far more rigid than the stock X-carve mount.Personally, I think the stock X-Carve Z axis is a piece of junk.
The big thing is having a suitable / compatible mount.
Back in the early days (Shapeoko 1/2) the community examined pretty much all the possibilities as noted here: https://www.shapeoko.com/wiki/index.php/Spindle_Options
That said, the Makita RT0701 and Dewalt DWP611 are the best bang-for-the-buck contenders, depending on what one wishes to do (and there are some clones of the former which are even better values as noted at: https://www.shapeoko.com/wiki/index.php/RT0701
don’t forget the Hitachi MVC12.