My brother has a 97 dodge 1/2 ton, he keeps breaking the front axle so rather then fix it we  want to put tougher axles in it keeping in mind that going to get 35"s or 38"s one day. What should we look for for a parts truck to get axles from? and why you never see these trucks made into big 4x4s?  

for the front i would go with an 03 and newer AAM 9.25 inc axle used under late model ram 3/4 and 1 tons, the axle would have all you suspenison bracktes in the right places and width i think is the same and its way strong for 35s or 38s think a bit higher then dana 60 for the rear a dana 60 70 80 from earlier rams or newer rams AAM 10.5 or go big with the 11.5 axle and your set for life!  

They AAM 9.25 is a good choice up front and it uses GM 9.25 IFS gears and carrier so aftermarket parts are availble. I would look for a D80 out of a CTD for rear or a AAM 11.5 if you want room to grow. I would not use the Dodge 10.5 AAM as unlike the 11.5 which is the same as GM has used since 01, the Dodge 10.5 is unique to Dodge and not related to or as strong GM 10.5 and has very limited aftermarket support.  

what trucks used the Dana 80?  

Pretty much all Dodges with CTD's until 2003. Some very early ones might of had D70's