What class of consumer are you looking to sell to? The stuff you put into tract homes and suburban McMansions is not the same thing you use for custom homes and high-end work.
A few things that will tend to differentiate the two classes:
McMansion-type jobs will not want to pay you for ongoing changes/updates/tweaks. You need to find something for them that is user-friendly on the configuration side.
Conversely, the high-end homeowners will tend to want you "on call" to make ongoing changes. It is a good revenue stream, but can be annoying at times when you get a call on a Sunday "We got a new DVD player and now my wife says the button that opens the curtains no longer works. We have 50 guests coming over for a dinner party in 2 hours and if she can't open the drapes the whole event will be ruined. Please come fix this ASAP". When you get there, the drapes will have started working again, the DVD player will still be in the box, but the multi-zone audio system will have reverted to French for the user interface. I am only slightly exaggerating.
For larger jobs you need something that has strong support for home theater/AV equipment, HVAC equipment (like 3-stage heating or cooling systems), pool automation, motorized drapes and doors, elevators, and burglar alarms/surveillance equipment. Also, it needs to support a variety of dedicated touch screen interfaces, mobile platforms, and ANYTHING that is visible in living areas needs to come in at least a dozen finishes and/or have paintable bezels that can withstand automotive-style painting/heat curing, not slapping some latex paint on it. Touchscreen layouts need to be highly customizable to rooms/zones/areas, displaying and hiding things accordingly.
For the McMansions, you need something that has a really good iPad or Android client, because they are less likely to spring for Crestron-level interfaces. The client needs to be customizable, but you can generally get by with a few "mode" interfaces (TV mode interface, lights, pool controls, etc.).
In the large jobs, lighting is likely to be controlled by commercial-style systems (Lutron, etc.), and of course you need tight 2-way integration there. Smaller systems will generally relay on powerline control or short-range wireless for all lighting control (Insteon, Zwave, etc).
The high-end stuff is also more likely to need the ability to support multiple properties, with modes/macros like "Going to Ski House", which turns back HVAC in the main house, and pre-heats the Ski House at the appropriate time, based on average travel time. Many of the consumer-level systems have no concept of there being multiple houses or properties, which can make interfacing two separate systems difficult.
Control4 is probably a good middle ground to start with. I would worry less about how you compete on the product side, because these systems will tend to be more bespoke than the average surveillance job, so you are selling yourself/your company, and your ability to customize things and make the system work for the homeowner. You may find your local market taking you more in one direction or the other, and can potentially choose an alternative platform later when you get a better feel for the kind of jobs you will likely be doing.
If you anticipate doing more mainstream and McMansion-level work, then I would check out Qolsys first.
