When you say "solo" Im assuming you mean as a box crew? Do you remember how many toons you used for it?
^^^^Yeah Ancient Cloak of Flames. Attunable, 17% overhaste + 18 regen/tic. I think haste still caps at 125% = 100% (spell/song buff + worn) + 25% (overhaste v3 via bard song&aura/clickies AA/some class boost buffs.)
So if you're running a bard your group's capped. If you're running a zerk, they're capped anytime "desperation" is active.
I guess I'll wait till anniversary and get one. (or keep looking in bazaar)^^^^
That's the easiest (and best) overhaste to get. Just ask someone to let you click it or pick one up in the bazaar and pass it around on all your toons. You'll need loyalty tokens to unattune it, but what the hell else are you using those things on.... amiright?