Gear scaling in pvp content at 99 or lower

Does anyone know of a site or add on, or method of calculating gear stats as they will scale to in pvp content?

For example, the arena grand master trinket.. gives +11 stam and a /use shield. What will that scale to at level 90-99?
The leather bracers from RFC scale to just barely below the rogue ones from MC. And the daggers from RFC are just very slightly worse than my boa daggers, when scaled 60-69. (Im still leveling)

I know that you can see certain procs on wowhead by sliding up the bar when you click on the proc itself to 99

Other than that, just test it.

Do many people event 90-99 twink?