If I could re-vote, I'd go with one of the HK 21. I did a lot of research for a PC I run in Fusilier's game and it sounds like a really versatile weapon. With its heavy barrel and biped, when scoped and firing semi-auto from box mags, it can serve as a DMR. With a drum mag, it's a SAW with more range and punch than equivalent 5.56mm weapons. Add in a conversion kit, when your T2K character invariable runs out of 7.62mm NATO, he can switch to 7.62x39mm AK rounds. And, according to Wikepedia, it's got 48% parts commonality with the G3, which, in the v1.0 timeline at least, would still be fairly common in the ETO.
Apparently, German KSK commandos still use a version of the HK12.