All you need in order to be able play Fallout 1.5: Resurrection is a full installation of Fallout 2, any version should work (no matter whether from Steam, GOG or CD/DVD). Resurrection already contains patch 1.02 for Fallout 2, as well as the High Resolution Patch for resolution options, and the engine tweak Sfall which introduces neat functional changes to Fallout 2. The installer will take care of the whole installation process.
If you happen to have any problems with installation or with running the game, we recommend checking the "Known Issues and Their Solutions" section in the Resurrection readme. Otherwise, feel free to send us an email or contact us on our forum and we'll try to help you. We're also interested in your opinion of the game and the experiences from your playthroughs. Lastly, let us know if you come across any bugs so we can fix them. Apart from the aforementioned forum and email, you can reach us here on ModDB, on our Facebook or Twitter.
Enjoy the game!