www.hptuners.com
ls1edit is garbage, handhelds are generic junk programs, and mail order tunes are a back and forth to actualy get the tune right, and even then it is only right until you do more mods.
hptuners is easy to use, it has a great built in data logger, and it opens up dozens more parameters than any crappy hand held ever will.
if you don't know where to start once you buy hpt? they have a tune dump on their site you can search
want to understand more about how to take advantageof the program? the program and their web site have tons of help files and how to info as well as a huge forum with experienced people who can talk you through anything. not to mention the number of people on this board that have and use their software.
basically, spend a little bit more than a hand held or mail order tune and be your own tuning solution for the rest of the time you own the car. hptuners can easily be added to if you buy other cars as well, they have hundreds of applications to choose from.