jason, if you're going to go with a retro bottom drain, do the
AquaArt one and not the Tetra. The tetra drain is plumbed from the top, so you will have a pipe running up in the pond that will be unsightly and give your fish something to bump into. The Aqua Art drain is plumbed from the side, so your pipe lays on the pond floor. Once a little algae covers it, it virtually disappears into the pond floor.
The Aqua Art is very light. As per the directions, you drill a small hole on top to avoid air trapping under it. It has 4 little feet that project out, and you simply put a rock on two or three of the legs to keep it weighted down and that's it.
When I close down my old pond in a few weeks, I'll be selling my current equipment. If you're interested, you can have my large Aqua Art Drain for half the price + whatever the shipping cost is. You can PM me if you're interested.