For the most part the American heads are better than the European ones. I believe that the exception is the Cosworth ones, which are rare and expensive. The Europeans even prefer the heads we get, I believe that it is in part due to the exhaust port layout. IIRC two cylinders on each head share a port.
Now what you may be able to get from over there is intakes. As you know the only intake option here is the Offy 4bbl. I recall seeing aftermarket intakes for everything from a single two to triple-deuce . To the best of my knowledge the intake runners are the same so you should be able to use those on our heads. There are also supposed to be some nice cast aluminum valve covers available. I have a set in my storage building that I believe originated over there, if I don't forget I'll get a pic of them.
I was researching other mods to do to mine during when I swapped it from the totaled 84 into the 86 body. Since I already have the Offy, Holley 390, Stage 2 Comp Cam, Metal Timing gears, Long tube headers Duraspark, and mildly ported heads there isn't much left to do. Only other things I could come up with were the valve covers, different ratio rockers (if you can find them), rocker arm spacers, and valve springs. Haven't looked into that stuff since I found a V8 to install instead.
Just a little hint for when you are searching, alot of people over there call it the Ford 2800 (for the 2.8L).