They are one of the larger suppliers of malto out there. You want to look at their Maltrin QD (quickly dispersible) line of Malto. Either the M550 or M580 works well and has the proper DE range. They have very knowledgeable people working the phones there and can also set you up with the information for a local distributor. *Scroll to bottom of page for contact info*
Here's the catch....it only comes in 50lb bags. The bags can range from $48 to $52 a bag...I paid $48? up here in Oregon but it was $52 in SoCal thru the LA distributor. Not too much of an issue if you are training high volume or have several people you can share a bag with. I just bought an extra garbage can and used a heavy duty bag liner to store my supply. I currently have about 40-50lbs of the stuff so will not run out anytime soon.
I have used this stuff for the last 3 years and there is no difference between this stuff and Carbo Pro. I think this actually dissolves faster then Carbo Pro and is MUCH CHEAPER ($1 / lb vs. $7/lb for Carbo Pro). Steven has a team member on his tri-team (a doctor and very fast triathlete) who spent time researching the Maltrin QD with his contacts in the nutrition field and now he and many members of the Ironheads use the stuff with great results.
Ok, enough with my Triathlon Public Service Announcement....just trying to save you all some $$'s so you can spend it buying other tri-toys!