In the security industry there has been an ongoing debate, it goes like this, the locksmiths say keep the bad guys out; alarm techs say let me know when they get there.
The cost of highly reliable do it yourself alarm systems make this debate obsolete!
Do some research on what features you want and what control provides that feature, be sure the system you are looking at has what you want, or can be expanded. Find a product in your price range.
Most systems are very easy to install, and most are wireless, some even offer monitoring, usually at an additional cost.