What type of foundation is best in an area with silt loam soil, cold climate, and high water table?
You have several foundation issues to consider: 1) deep enough to eliminate frost/thaw heaving, 2) deep enough to insure stability, 3) deep enough to resist seismic activity, 

1) There are lots of charts that will tell you the minimum depth required to reach the frost line. A slab on grade is NOT acceptable, unless it’s structural and tied to a “deep” structural foundation system. 

2) In order to find stable soil, you’ll need to go very deep. (Where I live we use piles or piers and go 70’ deep.) We use a geotechnical report performed by a geotechnical engineer. They drill over 100’ deep and take samples. Those samples are analyzed and they produce a report that allows us to recommend the correct foundation. 

3) If you live in a seismically active area, you’ll need to consider a “deep” foundation system too. If so, you’ll need an architect or structural (not civil) engineer. 

Your neighbors that build on piers, but still have problems, probably did not account for axial load and it settled rather than heaved. 

Depending on your soil conditions, you may need DRIVEN piles rather than POURED piles (piers). I’d talk to a local pile driving company and see what their costs are for various pile and pier foundation systems. 

Also, because you mention fluctuation in water-table, you’ll need to account for insect infestation.