Hello Balloo. What I would suggest is while sudying those systems, one must "call out" to you more than the others. One must feel more natural.
If your not sure, try finding a sparring partner, or a few sparring partners, and try each style and see which works for you better in a fight. Then you also got to decide which will be more beneficial to you and will help you achieve your goals. External styles are good while your young, but you have to learn how to internalise them as you get older or your skills will decrease. Some teachers dont teach that and you have to decide if you will be able to learn how, if not I wouldnt suggest an External Style. Internal styles, your skills increase with age, but take longer to learn and master. Styles like Bagua and Taiji are not only good martial arts, but they help you maintain and better your health. If you want to be a "minute made" master, then Internal styles arent right for you.
Its ok to even study ALL those styles, but you need to find 1 that you can master. You cant
master 5 martial arts. Its better to be proficient in one art than a smatterer in a thousand. Some people may be able to master 2 or more arts, but I personally know I would be confused if I was trying to master 2 arts at once.
With me for example, I actually was "drawn in" to Taiji by some past experiences before I ever seen Taiji done, then I saw the movie Taiji Master or Twin Warriors with Jet li, and that furthered my interest. Then in the military I started reading books to see what martial art I really wanted to learn. I read some books on Shaolin, I watched some movies, I read books on Jeet Kune Do, and the book Taichi Classics by Waysun Liao helped me make my decision. Now I also plan on learning Hung Ga, but Taiji is the only martial art I plan on mastering.
Then you got to decide what your martial arts weeknesses are, and how to correct them. For example, From everything I read and learned by research and through my teacher, Taiji is built to defend against Shaolin and Wudang, and the sticking and following can compete with most other styles. The only style that can destroy Taiji from my experience is a more skilled Taiji practitioner or a Hung Ga practitioner. Hung Ga consists of Golden Bell Cover, or Iron Body, so it does not retreat, and also has 5 animals, (snake, crane, mantis, Tiger, Panther), The 5 elements, and aspects of Taiji, Bagua, and Xingyi, so it makes it hard unless your listening Jing is very strong to stick and retreat, and even harder to counter attacks unless you know your opponents weak spot on thier Iron Body. So if you decide to master Shaolin, practicing Chen Taiji would be beneficial for you. The reason why, is the soft yielding of Chen Taiji, and the defenses it has from kicks, make it Shaolin's match. If you decide on Praying Mantis, Hung Ga and Taiji are good martial arts to practice on the side, so you have all grounds covered.
In the end the decision is up to you, we can only give advice. Then its up to you to take it or not, and decide what you really want to do. What else I would suggest would be researching the theories of each martial art and decide which one fits your beliefs best. Taiji=Daoisim, Bagua=I Ching, Xingyi=Yellow Emperors Classic, Shaolin=Buddhism, Hung Ga=Complete Reality Daoism (buddhism/Daoism), and animal styles are beliefs and personalities related to that animal. You must become that animal to truly master the art. Just to name a few. You must decide what is right for you and what fits YOUR personality the best. Good luck.