Hey Spitfire,
I'm going to let my maternal instincts cut in now. You're 18 years old and you dream of becoming an infanteer, so much so that your paperwork is done already. Unsure of whether you want to go Res or Reg, but know that you want to do this full-time. Perhaps your indecision in this area can be attributed to the point you bring up about your family and friends wanting you to go Res Force to see if you like it first.
I can tell you this, I dread the day my son looks at his father and I and says he is going to join the Forces. I dread this because he is my son, and I love him and I know what joining the military can mean. It means that one day he may be required to give up his life in the profession that he chooses. I do not look forward to this day, but I will give him my full support. Unfortunately there are few out there these days who can commit themselves to such a 'career.' Of course, if given the choice, many parents would not opt for their child to join the Reg Force with what they see on their television screens daily. Although for many of their children, this exact same scenario being seen on TV is what causes the itch in a certain populace to join. The will and desire to join and try to make a difference in the world. It is a calling that you either have or you don't.
By your very own words below, I suspect you have it. You have expressed your desire to go overseas, even knowing with what Units you hope to serve, and have also expressed your desire to do this full-time. You must follow your dreams. Being 18 years old, and about to make what is probably the first life-altering decision of your life, and your parents lives, I suspect that your indecision is based more on a desire not to hurt them. You have given us details below regarding your fitness and desires that tend to show that you are expressing your beliefs in your abilities to be an excellent soldier serving in the Regular Force.
Please sit down with yourself and think hard about the reason for your hesitation. Is it your hesitation or is it hesitation caused by how your parents may react? Once you have answered that question, you will know what to do in your heart.
Once you have determined that, sit down with your parents and explain to them why you have made the choice you have. You will find that they will support you no matter how you choose. Depending on your choice, their hearts may break a little, but they will watch their boy become a man in the process and they will be proud.
Regardless, the Military itself is a distinct family. Many others will support you who have gone through the same process. In a few years, no matter what choice you make, you will probably be building a family of your own (and wishing that mom & dad didn't live so darn close!!). At that point in time, your home is wear you hang your hat and what you make of it. Eventually your wife and you may have children, and if so, the circle of life will continue again as you sit back and fear the day your own child tells you that they are going to join the Military. It has been feared by many parents in the past, and will continue to haunt parents in the future.
Good luck with your decision making. Growing up is a hard thing to do at 18.