pulling power ?

[surreyboy]

hey every one , im new to the whole diesel world here & have been reading other peoples threads . what is the difference between a tuner & a chip ?
i have a 97 f250 HD 4X4 5spd with 360,000 kms. the truck runs great , i would like more power for pulling my trailer up hills & through the mountains . the only mods on the truck are intake , 3" down into 4" strait & a set of 315/75/16s what would you guys suggest be the best way to go ? i would like to have as much power as possible under my foot for when i do need it BUT i dont want to start breaking things either
a guy told me the best way to go would be a pre burnt chip , just plug in & go ? i know nothing about chips or tuners or good brands to get

thanx every one for the help & advice , its much appreciated