CHenry makes some good points about vegi-oil conversions, the thing that attracts me most about them is not having to worry much about the free fatty acid content of the WVO.
But he overstates the dangers and difficulties of making your own bio.
Yes methanol and methoxide are dangerous, but he makes it sound like if you get a whiff of it you'll drop dead (I dunno if he's selling something, but I've noticed that people selling competing technologies tend to overstate the biodiesel threats--not an attack, just an observation). He's overstating the danger quite a bit. If you use proper precautions with lye or KOH and methanol (ventilation, gloves, etc) your risk is fairly minimal and easily contained. People have been powering race cars for decades with methanol. Lye has been in your home for more than decades (you call it drain cleaner). It ain't plutonium folks, the idea that, as he put it, "one mistake WILL KILL you", is a bit melodramatic. Just use common sense, safety gear, and work in a well ventilated area, and the rest takes care of itself.
Sure you should keep it away from kids, just as you keep the liquor cabinet, the gun collection, and the dirty movies away from kids. And no you shouldn't get a load on while doing it, but having a beer or two while you work isn't all that hazardous.
Also, the time committment isn't all that bad. Collecting the oil is the worst part, and you have to do that anyway if you're running WVO. Once you get a system down, it's not too bad. But it's not for everyone either. I have the luxury of working from home, which helps. Once your processor is wired and running well, it'll calm down effort wise.
The other nice thing about bio is yes, you can go application to application. I sold some spare bio to another diesel enthusiast. Can't do that with veggie.
Ideally, the best solution cost and environmentally would be to do both. Use the bio to get the truck up to temp for the WVO.