Personally, I like brushing on emulsions. I try to design the brushwork to compliment the image. But that aside...
Epson piezo printers should make excellent coaters. I've thought of trying it myself, load enough solution for 6 sheets or so and print at such a heavy ink load that one or two passes through the printer exhausts the carts. I've loaded Epson carts with everything from filtered watercolor paints to gum Arabic to food colorings to scents (long story). Don't try a hot process printer (HP or Canon).
Personally, I'd only use the inkjet as a coating method, not an alternative to using negatives. If you're actually going to print the image instead of using a negative, you might as well just load the printer up for a platinum metallic ink. The closest I came to alt printing with the Epson was to load it with gum Arabic, let it dry, mist it, and sprinkle it with aluminum, brass, or gold powder.
You should probably start with something cheap, like a cast of CXX series (C80, 82, 84, etc) just in case a particular chemistry turns out to be a printer killer. You'll need empty spongeless carts. Platinum coats about 1 drop to 2 square inches, so about 40 drops for an 8x10 (sounds low, but there will be no overshoot). That's about 2 ml (20 standard drops per ml), so you could reasonably expect an Epson C80 or 2200 color cart to do about 6 sheets.
I'd suggest a first flush of the printer with Windex to clear the heads, then a second flush with distilled water. Then load with your alt solutions and print a plain colored rectangle. I'd use QTR to have all channels (or as many as you'd care to load) running uniformly, and at a higher than typical ink loads. That's why you may need several carts loaded, because I don't think these machiens can lay down enough ink to do 2 ml on an 8x10 in a single pass. You'll have to play with your ink load till you get the printer to run itself dry on the proper number of sheets. Do that "playing" with cheap ink, like MIS black (dilute 5:1 in Windex, if you really, really want to get cheap).
Have fun...
