If you mean you want it to have a better GUI than what is featured in the latest "official" build, then you should look into compiling the source code of eke-eke's latest revision- it features an excellent GUI and Genesis emulation improvements. There's even a few extra features to make it more like a real Genesis, such as cartridge lock-on compatibility (Sonic and Knuckles, Action Replay, Game Genie...) and cartridge hot-swapping (For that pesky Sonic 3 level select code :P) that you can toggle on and off.
If you meant that you wanted the GUI to look exactly the same style as Tantric's emulators, however, you may be out of luck. I don't think that'd even be considered by him right now; not only because there is already an official enhanced GUI version, but because he is also working on multiple projects as it is...