It's gonna be a lot of work, but if done cleanly like the one in the link you posted, it should work fine. A UDS is obviously easier and cheaper but the T design sure looks nice! As for the holes drilled between the two barrels, I agree with wampus that it will really cut down your heat transfer into the cooking chamber, which may lead to high fuel consumption. If I was building one, I'd probably cut a large hole instead and use a baffle/tuning plate in the cooking chamber. Then, I wouldn't be committed to one heat control method. Good luck and post pics.
UDS'-55&16, Akorn, Bar-B-Q Kettle, Drum Grill, miniWSM, cobweb-covered gasser. I'm JD.