Assigning things to the three bars

I am setting up my campaign and I'd like to maximize what I can from the roll20 system. I am going for AD&D 2E as a game system, and I need to think about what to put in the three bars (heart, lightning and pulse-thing).  My initial thoughts would be hitpoints, Thac0 and AC (armour class). Any users familiar with AD&D? What would you assign to those bars to make life easier?  Auras I have down for things like 'Detect Evil' (Priest Spell). Though it can only do square or circle, not something like 10ft by 120ft (I can wing it, no biggie).

I use them for Hit Points, Armor Class, and Movement Rate.

Mine show the AC, HP,Thac0, in that order. A actually put AC in the first circle i.e. AC3 so I don't forget! If the token in question can use a shield but normally doesn't, I put "4-3" denoting a AC decrease from 4 to 3 when using the shield. Some of my players use the Thac0 (3rd circle) for number of arrows/quarrels Which reminds me, I should make a macro for that!

Good stuff. Arrows too. Keeping track of ammo...

In my 2E campaign (if the character is low enough in level) I like to use the other two bars for 1st and 2nd-level spells for the day. I like the idea of using it for arrows, though.

I keep track of ammo as an attribute on the character sheet. It all comes down to what you most want to know, that's what should be in the bars (which don't even have to be bars)