HP ProCurve 2920 switch stack topology for TWO switches? Ring vs. Chain vs. trunk?

To quote yourself, "The stacking cost just isn't worth it at this scale". Yes, you get some better administrative options with stacking, but it's probably not worth it here.

Talking about stacking in general, with just 2 switches, only one stacking cable is necessary. Once you get to 3 switches or more, a ring is best because then any one switch could fail and still provide access to the other switch(es).

Just use a few links between the two switches in a LAG.

  1. it'll be cheaper
  2. you'll be easily able to increase bandwidth between the two switches by adding a port should that become necessary
  3. you can always upgrade to stacking modules later