It's really all personal preference. The fact of the matter is that good tuners will work with you if you are not satisfied right off the bat. That is the nice thing about custom tuning. It can be modified to your liking.
As far as which style of tuner to go with, most in the 7.3L world would say chip. They are easy to install, switch on the fly, and can hold numerous tunes. We have a couple different options as far as chips go if you are interested. Check them out
HERE.
Programmers can be good as well, as long as they can hold custom tunes. Most people do not prefer the "off the shelf" type programmers which cannot be modified. Unfortunately, there are only a couple options as far as custom tune-able programmers go for the 7.3L, and they cannot switch tunes on the fly. This is why they are not the most popular. However, we do offer one called the Infinity which is pretty unique. It is not only a programmer, but it is a monitor, datalogger, code reader, and diagnostic tester as well. It is loaded with a Ford Enhanced package which enables you to run injector buzz, cylinder contribution, and KOEO/KOER tests. It will also monitor 218-254 parameters on the 7.3L depending on the year. This is what I personally run, and since I do not switch tunes all the time, it works out great for me. Take a look at it
HERE.
Feel free to contact me with any questions you may have about tuning (or the 7.3L in general). I would be glad to help you out.