First off, I know very little about ATA's and how they work.
My existing DSL service uses the grandstream HT701. I'm pretty sure this was installed by Sonic after AT&T installed the service drop to the house. The HT701 has been fine for voice but lame for fax as it can only process a single page at a time.
t38fax.com recommends a configuration for it that allows for better faxing but it's at the cost of disabling common voice features (like caller ID) As a result, I've made a lot of use of the online Sonic fax service which is not as convenient in the home office.
I see Grandstream has newer products such as the HT802 and am wondering if this device might suit me better. It has two phone jacks on it and supports two configurations. However, the documentation says nothing about what you can do with the two jacks. Are these for supporting two separate phone lines (separate numbers) or for two configurations on the same line (like one optimized for fax and one for voice)? If the latter, I presume I could run two lines to my office - one for a land phone and one for my fax machine.