I am planning to order 3- bipolar 8-wire nema23 425 oz/in steppers (2.8 A) for my y axis  and 2- bipolar. 8 wire 640 oz. (6.3A) for the x.
I already ordered 5- Gecko model #213v drivers. I sure could use some help determining the right size size power supply for these. Also, if I buy Mach3 software. will I still need a breakout board? since descriptions say Mach3 "converts a computer to a 6 axis cnc controller". what does that mean? does that mean Mach3 replaces some of the hardware?
Thanks for your help

This is the 10' x 8 ' hotwire cutter I'm building. Each tower will weigh about 26 lbs in single wire mode and about 35 lbs in multi-wire/gantry mode.

http://www.woodworkforums.com/attachments/f170/238347d1351100728-chinese-company-cnc-parts-hotwire-woodworkforum.jpg

You dont need a breakout board but it is safer to have one, especially if you are new to this, also it will make connections easier.
What "converts a computer to a 6 axis cnc controller" means is Mach turns your PC into a software controller for CNC.
Hood

Thanks Hood,
Do you know of one you would recommend? I was looking at a Smoothstepper but it's a little pricey. I want one which can handle at least 5 axes, limit switches,  emergency stops but I don't know it this one does that..........

http://www.ebay.com/itm/CNC-DB25-Breakout-Board-/380269712447?pt=LH_DefaultDomain_0&hash=item5889d7543f

The Smoothstepper is not a breakout board, it is an external controller that works with Mach. What Mach does when using the parallel port is to plan the trajectory and also send pulses out of the parallel port. The max pulse rate from the parallel port is 100KHz but often you will struggle to get any where near that, 45KHz more likely.
When using the Smoothstepper with Mach the trajectory is still planned by Mach but the Smoothstepper generates the pulses. The pulses are very smooth and clean and it can pulse up to 40 times faster than the parallel port (4MHz) Also the external pulsing takes a big load off of the computer so things can often run a lot better.

With a stepper system you are unlikely to need more than 25KHz kernel, possibly up to 45KHz depending on gearing etc and as long as the computer can deliver a nice pulse it will work well. Mach does not work well with laptops though when using the parallel port but with an external device such as the smoothstepper that is not a problem.

That breakout you are linking to will allow you to control up to 6 axis and if you have your limits in series then yes you can also have them and the E-Stop and still have 3 left over for any other inputs you may want (Index pulse, buttons on a panel etc) If you are wanting to control a spindle as well then you would be limited to 5 axis and the spindle.

You can add a second port to your computer and have a second ports worth of I/O if you wish.

Hood

I saw newbie questions and since this is active still (sorry to thread-jack), I'm new to the CNC world but learning a whole lot really fast.  I have had my machine for a little over a month (4X8 ez-Router) and have, until recently, ran a few "for fun" jobs, as well as my first paid job with no problems.  This weekend I was making some final tweaks to my latest job and went to run it on some scrap wood that I have machined down to the actual thickness of the expensive material I have for the job.  I set my offsets up for my jig, ran my code, but it ran the job about .25"-.5" above the material, never making contact.  I went back and watched the videos on homing and zeroing and here's my question : if I touch my tool to the material to 0 the Zed axis, do I still need to "auto Z" with the button on the screen?

Nevermind on my last post, I just went ahead and zero'd on my wood, and its working right now!

My understanding is that you would confirm the tool in the spindle is the tool indicated in Mach's tool window. If it is jog tool to surface of part and "zero" the Z axis. If you have more than 1 tool and they are repeatable (I doubt it with a router but I have been wrong before) all tools will have the correct offsets. Well if everything was set up properly in your tool table.

Thanks Hood!

Everything is running correctly after manually zero'ing the zed axis(manual=jog down till touching and hit zero), so what is the tool touch-off plate used for if you physically place the bit onto the surface of the material?  Like I stated earlier, I had been using the plate without a noticeable issue, prior to this job, not sure what I did different this time for it to act all screwy. Thanks for the response though, fastest1

As long as the thickness of your touch plate is entered in the gage block thickness dialog box you shouldn't have any issues. Same process, put touch plate on surface, touch off and either enter the thickness of your touch plate and hit enter or by using your settings page.