Better is to finish this mod on renegade's basic.. after this project you can think about to change to UDK.. just in remind, it will need a completly rework, in models and textures, scripts and codings.. so it will take a while again until a playable release is playable.. and it is also not sure if RenX will give out their scripting works and other stuff, cause thats their creation and honestly i would also not be that happy to give out my hard work to a other mod.. so this isnt sure if you can take some codings from them or you have to copletly do your own codings..
ofcourse the w3d engine is old, and many new engines are really good now.. but you have to uodate your computer, and most new games are so complicated and mixed with reality that its not doing fun to play.. in renegade/reborn, you can spawn, choose your unit, buy your unit, run, jump and shoot... in other games you cant run alltime cause of "realistics" and so on..
just keep in mind, this mod is still alive... other mods died, tiberian aftermath for BF vietnam as example.. tiberian eclipse.. or whats about tiberian sun rising, looks also dead, no more news on moddb.. many hours, days, weeks, months and years hard work on reborn mod... finish this one, would not be fair for other reborn members or ex members if it will be canceled for a other engine.. i think those real reborn mod fans will play this mod, and maybe some other ppl that see this mod from friends or over internet.