where are you based?
thats going to impact on what you use significantly if you want to source natural branches. ive just finished completely this playstand for the same reason as you. im in australia, and its made primarily from eucaluptus branches. ive used a melamine base, VERY easy to clean. also a semi-round dowel along the base to catch fallen & rolling food bits and seed. you'd probably want some sort of harder wood, also make sure branches are dry and have not been allowed to stay damp/start to rot for long. dead branches still attached to trees or broken from fallen trees can be good.
this image was just after i made it, its now decked out with toys, climbing ropes, food spots, a woven mat to chew at. they love it. the only recommendation i can suggest for you if you have two birds, is have two high spots (as with mine, you can see there is only one. they are always tiffing for that spot). something ive been taught from my reptiles aswell is to bake all branches at 150C/300F for 15 mins in the oven to kill any nasties. otherwise a 90:10 water to bleach mix sprayed liberally and then leave the braches in the sun for a day or 2 to break down the bleach (i also use this bleach solution to clean the bases of the stand and their cages)
this cost me a FRACTION of what it would have been to buy one, and personally im much happier with it. go for it!