I'm going with Tiagra for this one, and I'm in full agreement with the last post.
Jake came with 105, and I loved it. ST-5500, so a few generations back now, which has a lot to do with why my new Sora brifters feel fine to me. I did swap out the rear mech for an XT shortly after I bought the bike, and of course it's still in great shape. Jake's gonna go gravel, I think.
The LHT may find its way on to the market. Not that I don't like the bike... in fact, it's pretty great on the road. I just have a lot of overlap between bikes, and if I can get a good price for it, I'd go for it. If not, I'm fine keeping it. I have a big basement.
Now just need to wait for everything to arrive, and I get to put it all together. It'll be a couple weeks or so, and I'll be doing some hilly laps and working on my base miles in anticipation.