When you've won DDO, you're supposed to use the button of winning. What's with this high reaper raiding thingie that you're talking about - I haven't seen it in the store?
OP, hopefully you enjoyed your journey through all those past lives. I think your future plans are like playing a different game entirely compared to the past 10 years you've spent in DDO, so please be prepared for the possibility that the experience might not match your expectations.
The biggest thing that you didn't really ask about has nothing to do with the build or the gear - it's people and playstyles. Others in this thread such as Kimbere (no relation, but I've pugged with him a few times) are far more experienced at raiding and high reaper, and his advice above looks pretty solid.
Instead of mowing through packs of mobs, you'll need to know and use tactics, kiting Doom reapers properly, taking care to not blow up the Vengeance, memorizing raid mechanics, etc. Rather than needing to do it all, you need to fill a role and do a few things well. Really well.
From what I've seen on Orien, plenty of LH raids get posted, the occasional r1, and very rarely, some r3+. For anything higher, you'll either need to be invited to join one of the handful of endgame guilds on each server, or get to know them well enough to be invited to join their mid-reaper runs on a regular basis. It might take some time - along with running LH raids for experience, start hitting r6-r10 quests to gear up, and you'll start to recognize the same names leading and joining the groups. Get to know some of them, be a reliable and useful player, and eventually ask about reaper raids.