I have an oversized Sixbuilder I want to get rid of... PM me for the details if you want it. The rest of the oversized G1 KOs are fairly hard to come by. Bruticus is by far the most common, but still goes for about $200. There's also a white Prime w/trailer and roller, Defensor, and I think Superion. I'm pretty sure there's a Smokescreen reshelled as a Mercedes out there somewhere. There's a remotely newer Hot Rod KO but it's only maybe 10% larger. Robot Masters Victory Saber has had an oversized release as well. If you want BIG, go for the 45cm Fire Dagwon (from Brave) KO. I know I'm missing some, but there's a place to start. EDIT: The guy I originally bought my Sixbuilder from also had some Sixturbos.
This place has the giant Superion Bootleg.http://www.toyhell.com/ Click on the unlicensed bootlegs. I think I purchased from them, a long time ago, and didn't have any problems but I can't make any claims about them now.
that's a custom job,i believe.regular ko's are all i can find...try walgreens of all places for low quality g1 combiner sets for about $5.i personally broke mine,but that was a mold variation,so i can't vouch for what you might get.
I managed to get an oversized set of Sixwing (I think that's the name, the micromaster jet/heli combiner team) at a KB outlet some time back. They turn up in weird places it seems.
i can't find any sort of KO in Portugal... and i would KILL to get one like DavidLoPan got in ebay...
The project of repainting them to resemble G1 Defensor (and maybe get enlarged reprolabels) is customization; the enormous Defensor itself is an actual oversized KO set. And I doubt Walgreens is accessible to someone in Portugal, which doesn't have the big KOs he wants anyway. The oversized stuff doesn't seem to appear that often aside from Asia, so getting lucky on finding eBay auctions, or contacting eBay dealers that have regular access to such KOs, are the only real options.