I've never gotten a bent rail (and I've bought a lot), only the ballscrews were bent. I don't know anything about chinese drivers, but 1/128 microstepps sure seems overkill (if that's really one step pulse per microstep, you'll be very limited on your max speed; my 1/16 microstepping actually limits me to about 350 IPM, since the computer just can't provide pulses any faster trough the parallel port).
I would have gotten the rails and screws from Chai since there's more feedback about the seller, but since you already got them from another seller there's not much to do until you can and want to cancel the order.
How many ballscrews did you get? As you got a 4 axis driver kit I'd assume you got 4 ballscrews (2 identical for the X axis, to prevent side play which would be notorius with a long gantry). Who got that stuff from lmb2008 or from the other seller you mentioned? What lenghts did you buy?
By the way, and if you want and are still on time to cancel the order, I insist that a G540 would be a far safer bet than getting chinese drivers, and might save you a headache in case of a defective driver, bad documentation, driver lost in transit or any other problem. I'm actually considering a G540 for a small hobby level machine I'm building, knowing that there are sub-$100 TB6560 based chinese boards (which are crap, lie shamefully about their specs and burn just by looking at them).
Is this the kit you got?:
4 Axis Nema 23 stepper motor 425 oz & Driver DM542A CNC | eBay
The included PSU is crap, your motors would crawl at 24V. If the motor's data is right, the maximum/ near ideal voltage for those motors would be about 96V (by using sqrt(inductance) * 32).
Also, check the forums for info on Longs Motors, that's the first step to know if you'll get support or a good product (I do that kind of research with every single crucial part you get). If you have doubts about anything just ask, there's full of people you'll nicely guide you in the right direction. You could start here:
http://www.cnczone.com/forums/cnc_pl...ngs-motor.html
This is another nice alternative that might be cheaper than getting a Gecko, and their support is great:
4-Axis Monster CNC Stepper Motor Driver Kit - 4-Axis Monster CNC Stepper Motor Driver Kit
That probotix kit matched with a 40V or so power supply would performe quite nicely.
Believe me, change the drivers, you'll happier in the short and long term.