There's really no point in whole replacement arms, they do give you infinite amount of adjustment, where as washers would only give you +.25 deg, or +.50 deg, etc. You can get infinite adjustment too with the washers, just gotta grind them down, but there's really no point to get it that accurate.

And whoever said that the washer and bolt trick is cheap and not safe. Well, I have seen more than one set of those ingalls replacment arms snap off at the ball joint. How safe does that sound? If you take a look at one, it is really weak at the area they pressed the tubular steel together and attached to ball joint. Not saying that they WILL always break, but after seeing a few sets snap off, I am positive I don't want them on my car. I think they tend to break more when you set them at more extreme angles.

Lastly I have noticed that shiming the rear upper arm will mess with your toe, and I think if you push the upper arm out too much, you won't be able to keep the toe in spec anymore. Not sure about this though, that's what I have noticed when I get my alignments done. Because if you look at how the rear toe is adjusted you will see it has very limited amount of adjustment. This might not be the case though, because I never tried shiming it more than about +.75 deg, so I can't say for sure.

So all in all, I suggest you use the bolts and shims method,