I got permission to sink a few structures into a 20 acre river-fed pond. The maximum depth of the pond is 20 feet with the average depth being 8 feet. I will be creating structure that rises about 4-5 feet off the bottom.
I just saw some of the old posts showing X-Mas trees lasting over 5 years and I am able to get at least a dozen of them. Or I can spend some money on some PVC that will last longer.
I want to arrange my "trees" in a bucket of concrete so that they point upwards from the base at a 45 degree angle. I figure 3 trees per bucket at opposite directions would make a nice area of structure when clustered in groups of at least three buckets.

Should I use X-Mas trees or fabricate PVC trees from a 2" trunk and 1/2" branches?

I plan on sinking most of this structure in 6-15 feet of water for good summer and winter fishing structure. And as far as I know, this pond stratifies at about 12-15 feet during the summer.
Any good suggestions?