Steppers for Converting Sieg X2 to CNC?

[irving2008]

I wish I knew more about the maths of this stuff currently but it'll come in due course I'm sure.

In the meantime though, I think I spotted something of a bargain that might be perfect for what I need for the X2 to get started, with 3 options I'm pondering on. Yes I was going to try on the dirt cheap with the steppers I've got but these kits are cheaper than I thought, and viglink sent me a few £ earlier today that helps so I'm thinking it may be best to just get a kit with all the bits needed from the outset.

I found this first kit for £110 inc 3x 270oz steppers, driver board, and PSU delivered.
The 270oz steppers should be ok from what I've seen but I'm not hugely keen on the single combined driver board & how good it'd be. Plus I don't know if 270 is enough for my Z axis. I do have an air ram fitted so I'm guessing so but still....
�Free SHIP】 3 Axis Nema23 Stepper Motor 270oz in 3A 4LEADS 3Axis Board CNC | eBay

So more realistically there are these two:

3x 435oz steppers, 3x driver boards, breakout board & 2x PSUs - $299
�Germany SHIP】3 Axis NEMA 23 Stepper Motor 435oz in Single Shaft 4LEADS CNC | eBay

3x 425oz steppers, 3x drivers, breakout board & psu - $319
�Promotion】3 Axis NEMA 23 Stepper Motor 425oz in 112mm 3A Driver DM542A CNC | eBay

Wanted to do it cheap (in my nature) but these kits look great value and I'm thinking I should bite the bullet here.
What I'm curious about is why the kit with the higher power steppers (435 over 425oz) is cheaper and includes 2x PSUs instead of a single one in the dearer kit. Have I missed something?!

Appreciate comments on these - they look just the ticket and am VERY tempted, but don't want to be rash. Not too rash anyway...

Don't touch last one, 9mH motors are not great, needs to run on 80v+ drivers.
First one is poor, single board and only 24v

Second one is best of bunch, uses reasonable steppers @3.8mH, but these ideally want 4.2A and the drives only give 3A RMS, 4.2A peak. Also PSU is only 36v. Not sure how you use 2 psu across 3 drives; you can parallel up PSUs, but not generally a good idea.