Marine corp job selection

In the marines there is one thing and one thing only that i wanta do and that one thing is marine corp infantry. the term infantry means soldiers or units who fight on foot.  my friends this is what i dream about. i myself am an adrenaline junkie and this would be what i need to get my fix so to speak.the marines who have this job are  nicknamed grunts because of the hard strenous work they have to do.  since i was little i always admired ground pounders they have one of the ruffest toughest jobs there is. the job requires you to carry heavy packs while covering great distances on foot. infantry are the guys that you see kicking in doors storming houses. they are the front lines they sleep in fox holes that they dig. its a tough job which is why i like it because i like challenges. the pack they carry consists of everything the marine needs to survive for long periods of time because they are very rarely not fighting in some confrontation. this job is almost full so i had to pick a fall back job. which i chose combat support this is artillarary.( big cannons and tanks) instead of storming houses i would have a tank or cannon firing into the house. this is more a thinking mans job and i would never be set out first fight because i would only be used for support.  whatever job i get i will be pleased with because i will be a united states marine and that is an honor in itself .