No you cannot adapt that frame for a Gates Belt Drive, however there are a ton of great bikes with Gates already on it or frames that are ready to accept a belt drive that you can build up.

I wouldn't put a bunch of money towards the bike either ride it as is or save up your money towards the bike that has the features you want. Gates Belt Drive systems are awesome and well worth it but I would get something already built up personally it would be easiest especially in figuring out gear ratios and belt lengths since it is already set up and calculated.