If you can swing it ... I would buy the pieces you need separately and start by having a plan on paper - Which matches how you plan to light the scene 'most' of the time. I second the motion to stay away from continuous lighting because for portrait your going to need to work harder to control it.
- Living Rooms have windows, and windows add ambient natural light ... Where you setup could really impact the look of the pics
- Make sure you buy a rigid backdrop support just in case you need to shade the window light with heavy muslin (or layered)
- Big Octabanks and Strip Banks with egg crates make for nice portraits (umbrella's maybe not so much in the house ... always some stray light there)
- Don't forget the reflectors and flags and clamps and lightstands (air cushioned please)
- Also, C-stands work great and if you get the collapsible turtle bases they can tuck away (very sturdy, but wicked heavy)
- Apple Boxes or Sitting Props (standing gets old, and old people really dont like sitting on the floor)
- A wireless or cable shutter release
- Flashy Sync Things (Pocket Wizard, SkyPorts, or cables ... whatever your budget can afford)
- A box of fine chocolates for your significant other and a thank you card
- A 12pk of Gum or Mints for you (because photographers with bad breath = yuck)
You could get away with lots less ... and plenty more ... but whatever you do, make sure you get the chocolates, card, and gum!
Best of luck to you
Post Pics when done please!