The sidedraft carbs are certainly easier work on. The SSD config has the additional advantage of shared plenum versus individual runner for DSD, something I hadn't even considered when I first heard of SSD's. This allows for better idle and off-idle response due to the fact that there is a more consistent vacuum pressure across the intake runners, whereas the individual intake runners of a DSD do not share an intake plenum, and therefore you get vacuum pulses at the carb throat. This is great for higher rpm's but not so great at lower rpm's.
Now that I have strayed from your original question far enough... the only issue that you will probably have to deal with when working with an automatic, is if there is a kick-down cable. I am not familar with the automatics so I can't be anymore specific than that.