I am going to order some trail tough  weld on lower shock mounts today. Where on the axle do I weld them on? I am thinking near as possible to the stock location since I am using the stock upper mounts. Is that right?

location depends on lift, tire size, and rim backspace.

You need to be sure the shock will not hit anything when suspension is cycled.

Back of tire, leaf spring mount plates could be close areas.


You did not mention whether front or rear, but my lower mounts are more towards bottom of axle housing.

Fabbed mounts from angle & cut off mounts from original spring plates....

As ecoast said, You need to be sure the shock will not hit anything when suspension is cycled. 
On my Tracker I moved new shock mounts up to keep them above the rocks.  As I have lifted it quite a bit I got a set of Corwn Vic shocks which then bottomed out, requiring lower bump stops.  (Topping & Bottoming out your shocks will ruins them quickly.) 
So no mater what you are putting them on, make sure the shock will not hit anything when suspension is cycled, and the shock travel is not the limiting factor.
An old seat belt can be used for limiting straps to keep from topping out on the shocks, for mild off road use.  Hammering it will require better straps.

Ok, Ill make sure they dont hit anything. How about the angle? Does it matter if they angle inwards or outwards?
I was thinking about making some out of angle iron but wasnt sure if it would be strong enough. My buget got tight so I couldnt buy the trail tough ones and  I ended up making them (there not done yet) from some flat steel. I still need to get some bolts, I couldnt get the old mounts off the spring plates.