Well the overall length of k-car and l-body struts is about the same, so the Impreza AGX's will work in that way.
You're drilling new holes to match the spindle anyway, but since k-car and l-body spacing is the same they work there.
Both l-body and k-car strut tops need the strut shaft to be turned down as pictured so that the shaft will go all the way through the top and pop out the top. So if you use either one of those, that part of the mod is the same.
The neon strut tops probably wouldnt require you to cut the strut shaft at all, because neon struts come the same way those AGX's do as far as the thread depth. Neon tops also fit the l-body strut tower holes with their third stud knocked out.
Also, since k-car springs fit the impreza strut lower spring perch, you would probably use some kind of k-car springs, and k-car springs should fit the neon upper spring perch because im using neon springs on k-car strut tops so it should work the other way as well.
So with all that... im pretty dang sure using the impreza struts, k-car springs, and neon tops will work fine, and you may not even have to cut the strut shaft.
Or, if l-body front springs fit the impreza strut, OR if you go coilovers, you can keep your l-body strut tops with no mods other than cutting the strut shaft.
If you wait for someone to do it, it may be a while.. Why not be the first? If it dont work for you, someone will buy the AGXs off you anyway