Don't know much about systema but if you don't have access to BJJ try some wrestling which is pretty much everywhere (you can learn a lot about clinching, takedowns and working on your grappling base. If you don't want to take up wresting try some hapkido or aikido, both are great for SOME everyday real life encounters. You could learn some good wrist locks, pain compliance moves etc.
In my personal experience BJJ combined with thai and regular boxing are the best (BJJ chokes are unrivlaled in real street situations) But if you have no access try the above mentioned arts. The thing that sets thai, regular boxing, wrestling and bjj from the other arts is that you train to get use to contact. In most traditional arts you learn some good technique but have too many forms and showboating techniques that you dont use during sparring.
If you want to be effective in real life you need to train as you would in a fight. Work your BASIC boxing, bjj, wrestling and thai combos dont worry about the kata BS if you want to learn how to defend yourself. If you watch UFC, these fighter have good BREAD AND BUTTER combos both on the ground and on their feet. Most of them stick to that.
Sorry if I offended traditional martial artists on this board but I am speaking from personal experience. I have practiced TKD on a pretty advanced level and have seen many of those guys get hurt in the street. Bruce Lee had the right idea about martial arts. If it was not for him their would not be a such thing as MMA. KEEP AN OPEN MIND WHEN YOU TRAIN, don't use it if it doesn't work for you. JMO!!!!