Unfortunately there is no placeable silos as yet but there is an "alternative tipping" mod which you will find at http://fs-uk.com/mods/view/30700 This allows you to tip your grains etc on to the ground anywhere on the map.
You will also have to search that site for a bucket to pick them up again as the default ones don't have this option.
Not as good, I know but it seems to be the only alternative at the minute.
I did see and try it, but it wouldn't work for me, not as a placeable, that is, no triggers. Plus, the alternative working silos are one the same silos, they all share the same goods (the placeable pile doesnt).So, you unload your goods in the silos on one end of the map, it is automatically available also in your on-farm silos or any other silos on the map. I dont like that, makes things too easy and odd for my taste