I prefer the look of the T towers. I have no experience with either, but it just seems shinier. I've heard of some folks taking their existing 2 tap column and squeezing an extra tap into it. Thought I'd mention it because it may be an option to upgrade what you already have.
My keezer I went with front taps and shanks. Looked into half height kegs for the compressor hump and then running a tower and said screw it. Build the collar, drilled through it, 4 taps, done deal. Took less than 6 hours work time, notably more for various layers of stain and sealant to dry.