Do they make wedges for straight-axle dodges so you can reduce the driveshaft angle and reduce binding if you cant lower the t-case?

Yes. Here are some of the better ones.
http://www.suspensionconnection.com/cgi-bin/suscon/scan/fi=products/st=db/co=1/sf=category/se=Miscellaneous/op=eq/nu=0/sf=veh_make/se=Axle%20Shims%20-/op=eq/nu=0/ml=25/tf=category/to=x/tf=veh_make/to=x/tf=description/to=r.html

I say better because they are a bolt on piece made of steel. You can get cheaper aluminum garbage, but then you stand the chance of one breaking and falling out since they don't bolt on they just sit between the spring and perch.

Would they fit on the front axle? And what degree wedge would I need for a 5in suspension lift?

You dont want to add them to your front axle as it changes your caster angle(thats bad, dont change it).

If you are getting a vibration, you need to change somthing with your driveline. Not knowing what year/make/model etc... you have its hard to guess.

Well, I looked at it the other day, and I found out it has shims on the front axle. Its a 76 w100 powerwagon with a d44 front, fulltime4x4 and a 5in susp lift. I can't keep a front ujoint in it for some reason. It doesnt really vibrate or anything. I towed a vehicle to a junk yard and back one day (about 12 miles both ways) and it didnt blow out until i turned to go back in my driveway. Could it be a bad wheel bearing or one of those ujoints by the knuckle on the outside by the tire? That just went out on me too. I'm gonna buy some different axles for the front and rear in a couple of weeks too, so hopefull I won't still have the problem.

I would double check to make sure your transfercase has not slipped into "Hi-Loc" when it should be in "Hi". My old Ramcharger started losing U-joints right and left when I found out that somehow it had shifted into the loc position. A very slight binding when you turn will be normal with the full-time transfercase, but major binding is not.