Yes, as far as I know all keyless entry systems are designed to shut the car down if the brake is pressed without the key turned to the run position. When adding a system to a vehicle that has factory keyless entry it adds a bit of complexity to the install but shouldn't be a problem for an experienced installer.
I have come to see keyless entry and remote start as being very beneficial, all of my daily drivers have both features. My wifes Neon didn't come from the factory with power locks, but it nown has keyless entry/RS/alarm.
As far as brands go Viper is often considered top of the line (although I have had my ass chewed by car audio pros for saying so), and are well known for working well and having good warranties. Viper is made by a company called Directed Electronics Inc., who also market the same hardware in different packaging to different customers. Valet is DEI parts sold mostly through electronics places who also sell Viper, as a value line. They also have lines available that are marketed to the DIY types, they use the same hardware and often include the same features, for very attractive prices, however it is vitrually impossible to get warranty replacements on these lines because they are not installed by a certified DEI installer.
I install these parts myself, but I am an electronics engineer and have a Degree in Automotive technology, to top it off I work on auto electronics and drivability at a dealership, so I am prone to take certain knowledge for granted.
If you are very familiar with automotive wiring and electronics you can install this stuff yourself in a few hours. If you do not know exactly why you will need relays to make the keyless entry work without reading the manual, you probably do not have the expertise to complete this project safely. Installing these units requires cutting several wires that any one of can cause your car to not run anymore, this is not something to take lightly, a mistake can leave you stranded, and I gaurantee it will be at the worst possible time.