Hi,
Only one suggestion, HP E or V-series "stack" is not interesting because it's not real stacking or IRF (VSS, bonding) functionnality. It's only a one point configuration features.
If you only have to switch to manage i suggest you to configure them independantly. In my mind a would only form stack with identical product family. 2810 with 2810 (24 or 48 ports), 2510 with 2510 (PoE or not etc...).
Bye.