Ideally I wanted the Hi-Torque Mini Mill with solid column, large table, R8 spindle and Gas spring from Little Machine Shop (USA), however being in the UK, I had to adjust my requirements somewhat based on what was actually available.
I dropped the SX2P as I wanted to convert to CNC and there is very little space under the saddle, of what is effectively the same X and Y axis as the SX1(L/P) mills, can still be done, but more effort required and most other conversions use the thicker X/Y castings of the SX2.
I ultimately opted for a belt drive SX2 from Axminster as they happened to be changing their paint colours and were selling off the 'old' coloured ones at a decent discount.
I have since fitted my own gas spring (on the side rather than inside the column) removes the 'rubbish' factory spring mechanism – massive improvement in Z axis stability.
Converted to R8 spindle, spindle from Arc and bearings from ebay – took about an hour, MT3 spindle will be used for 4th axis, intention is to fit a power drawbar that uses Tormach style tool holders, I already have the Tormach R8 collet.
Converted to solid column and longer X axis with solid column kit from Arc – took about an hour (left over parts can be used for even bigger X and Y options – see Hoss Machine), refitted the gas strut on new column.
Igaging scales and Yuriy's toys DRO app on £42.00 tablet until I have the CNC parts machined and fitted.
CNC conversion is still a work in progress, I now have all of the raw material and am most of the way through the electronics, so maybe this year, but don't hold your breath.
loads of options available with one of these mills and plenty of examples of what can be done to them on the web.