@Adropac2: As mentioned, the T2002 engine fulfills the job as a Turrican with editor quite good.
Click the link in my signature, to see, what is possible.
Download "T2002Setup.exe", "T2002E_Update.zip" and "T Starter 2.7 (plus Mono).zip" at http://www.turricanforever.de/
in the download section.
Fist, install the game, then apply the Update, and then extract the Starter into the game directory. To play custom level packs, execute "T Starter.bat". You can download every level pack with it. I recommend Underearth, Morgul Returns and Metroidican for a start.
You'll find the T2002 level editor at lvl/Editor .
Team Pekaro allowed us (The http://www.turrican.eu
guys) to publish the flight level editor, too. If you want it (We didn't release it in the open yet), or have any questions regarding the editor, send me a PM.
@Exl: If your Doom maps actually are DoomII maps, I'm interested.