Alas! The cheapie psuedohistorical toys I found will not suffice for giants. They had some Powhatan Indians (now that's specific!) that might have worked for hill giants, except they weren't large enough, being barely 1.25" tall themselves; they also had knights and pirates ... but no vikings. How can you have cheapie pseudohistorical toys without having vikings? Scandalous.
So I bought a boatload of prepainted plastics from WotC in the after-market. I managed to get a couple of good deals via Troll and Toad and eBay. And I'm going to keep looking for those vikings ... they've gotta be out there somewhere!