27" wheels may limit you in tire choices. And it's probably a freewheel hub, not as strong as a modern cassette hub. I'd look for a bargain on 700c wheels with an 8 speed cassette. You might have to spread the rear dropouts a bit, not a big problem.
I agree a front triple would be nice for loaded touring. And that may require a new bottom bracket.
I like touring with brifters, but some don't think they're reliable enough. I just priced some used low-end Shimano Sora 3x8 brifters at $50 on eBay. And you may need a new compatible rear derailleur.
You can upgrade to dual-pivot side-pull calipers, maybe the best choice in rim brakes.