I'm no expert here, but I've been doing some research on building a servo based system.
Geckos, G320/G340 run 'brushed' DC servos only. Brushless DC servos and AC servos are incompatable due to differences in how they are driven. Brushed motors are cheaper and easier to drive so are the most common in hobby based cnc. Anoter company, Rutex,
has brushed and brushless drives. They also have higher voltage capabilities 100V vs. 80V for Geckos, and a model with 40A capability vs. 20A for Geckos. They will also run with TTL and differential encoders, as Geckos only run with TTL (without modification). That said, the Gecko's are powerful enough to run large metalworking mills, plus the end user support is vastly superior to Rutex. So I recommend sticking with Geckos.
Ebay is a GREAT place to buy this stuff;
This would be a nice ready made CNC Gecko based control with power supply and motors included (powerful motors, should be overkill for your needs) if you have the $;
If you would rather build yourself, here are some large/powerful motors that again would be plenty beefy;
These would need encoders added as mentioned in the description.
These already have encoders and would be quite nice;
Your next thing would be a DC power supply. For high power systems, the power fluctuation can be murder on standard regulated/swithched power supplies, although some have had luck. Most, go for 'homebuilt' unregulated power supplies. You will have to determine the motor specs; volts and amps to properly size your power supply (Geckos take a maximum 80V and 20A per axis/motor). Check out these links for nice power supplies;
under the 'Estore';
Also, Mr. Doug Fortune has some nice PS's at www.cnckits.com. However, either my address is bad or his site is down right now.
The G2002 is a new Gecko product as yet to be released. I don't know when. It should have some great features. However, if you buy G320's and decide to upgrade when G2002 comes out, you will be able to sell the G320's no prob.
As for software, check out the windows 2k/XP based MACH2 at
It is a fully featured program that works great with Geckos.
which seems to be temporarily down as of this writing.