I'm surprised nobody has mentioned quinoa in this thread. Sure, it isn't a protein powder, but it is a vegan source of the full range of amino acids. So trying to get a complete amino acid profile is as simple as adding quinoa to your diet. I've personally just used it in place of rice, or with a mixture of rice and barley. I've even had quinoa sushi at a restaurant before. Here in Portland we even have quinoa pancakes at a couple food carts.
When it comes to protein powders I got a few different kinds to try from trueprotein.com and didn't have any issues with them being gritty. Then again, I usually put a banana or two into the mix though, which probably helps. Or I put some greens in there blended up well, and with plenty of water or soy/rice/almond/hemp milk as well. I don't have a real preference as far as the flavors go, but I did find that although I couldn't really taste the mint in the chocolate mint, it did lend it a fresh taste. And being able to customize them with not just different flavors, but a vitamin mix and/or electrolytes is a nice touch also, and not much more expense.
The vegan personal trainer that told me about trueprotein.com had a code for 5% off too, so feel free to use EDB949 to get a little more of a discount. Also another hint for the site, the S&H gets more reasonable as your order gets closer to say about $50, so about 8Lbs of powder. You can get variety by getting 2Lbs of each kind you want to try. I'll be using the site myself for when I hike the PCT, as I'll be having a good deal of the stuff mailed to me each week while I am out hiking 20+ miles a day.
Gnarly GA->ME 2007 & PCT 2011