CAVALRY GUIDE:
As far as I can, try to group cavalry units in a single Corp, then give the Cavalry Perk to the Commanding Officer (+Charge Damage Bonus). For small engagements with small brigade allowance, at least 1-2 Melee Cav. units are mandatory.
One of the uses of this type of unit is rearguard/flank vigilance, supply train and artillery lifesavers (keep them close and hidden if possible).
The Weapon Equipment depends on your tastes, Armory quantities, and your $ expenditure limits, but here I list my own preferences, sometimes a compromise between cost/efficiency ratios.