Hiya, welcome to the forum!

I've used Rhonmac is the past, long story short - I ordered 3 stepper motors and they took forever to come. I think they are just middle men/resellers, so it's probably the case that your not buying anything you can't just get off eBay anyway ?!? Though I haven't looked (yet) as like I say they couldn't get 3 steppers right so I've never been back to their website...

The High-Z are very popular, they do have 1 or 2 things that could be improved but what product can't be criticised if that's your inclination...

The High-Z would be my choice of the two here, but ultimately my real choice, would be to build my own.

.Me