As GOG excels at making old games work on modern platforms, I would be thrilled if they made Heroes of Might and Magic 3 and Unreal Tournament 2004 work on modern Linux distros. Those games have Linux clients already!
Actually, UT2004 already works on modern distros just fine, albeit with a bit of tweaking. Here's a guide I wrote on getting UT2003 to work, and much of that applies to UT2004 as well: http://greatemerald.xmpcommunity.com/index.php/articles/general-articles/264-running-unreal-tournament-2003-on-modern-linux.html
As for HoMM3, the native Linux version is really old. It's Restoration of Erathia only, without the expansions (Armageddon's Blade and Shadow of Death), so running the Windows version through Wine is a better solution.
I already own Unreal Tournament 2004 thanks to a compilation disk I bought a few years back. Came with Unreal Tournament, Unreal, and Unreal 2 as well. Nevertheless, I would buy Unreal Tournament 2004 again, and off GOG at that if they start to support Linux, along with gifting the game to several of my friends. I would be willing to try your method, but persuading my friends to do so is a different story! Regarding Heroes of Might and Magic 3, I guess it's the only option. Wouldn't this
be beneficial to the cause, however?