So as promised I'm going to give a budget and links to the type of equipment you should be buying. Trying to keep it to the minimum without going into the realms of cutting costs at the expense of the content.
Equipment
Stills Camera. $1300 Nikon D90 Digital SLR Camera with Nikon AF-S DX 18-105mm lens This looks like a really nice camera. There are cheaper ones but I feel this is the better one. You will need to add the price of flash light if you want to shoot outdoors and use it for fill in flash. Otherwise you will be bound to places with power so you can use you studio lights or suffer from heavy shadows. Even working indoors a camera mounted flash light can be useful for shooting couples and lighting all the places that need to be shown. Experiment with this set up to get great stills, for tours.
Video Camera $2,000 Sony HVR-A1U Camcorder - professional - 1080i - 3.0 MP - 10 x optical zoom Without going over board on the budget this looks like a great buy. Not sure about the camera mounted mic. Try it out and see how it works. You will need to add the cost of an extra battery and a tripod of mono pod. Unless you have rock stead hands.
Studio Flash lights with accessories. $2000 Multiblitz Profilux Plus 400 Essential 2-Light Kit (100-260VAC) There was so many options here I was spoiled for choice. Ranging from a few hundred dollars to thousands. I went for Multiblitz Profilux because I have used them and some of the cheaper options looked very under powered IMO. You can use the sync lead the kits come with or invest in a couple of auto triggers that mount on your camera. Use one at a time and keep the other handy in case it goes down. Don't be caught out.
More options. My advice is to go to a shop and see what suits you.
Video lights with accessories. $1500 Studio & Location Lighting:Flat Panels:Spectrum Flat Panels We've been using these systems and in normal rooms they're good. In large rooms you need a lot. The downside is controlling them and they're large. If shooting HD you need a lot of good light to bring out the best result. There are some cheaper options do you need to search around and again get to a proper shop to try them out.
This looked like an alternative that might suit some. Have no personal idea how good they are. Any one here use them?
3000 Watt Photo Studio Lighting Softbox Video Light Kit Boom Set & Carry Case - 15 Photo Bulbs
Flash meter. $234 Shepherd Polaris Dual 5 Digital Flash Meter with 5 Degree Spot Meter Attachment A flash and light meter gives you control over the light hitting the models and light being reflected into the camera. You need to take readings from all main points on a model, head to foot and especially the important bits.
Learn to control reflected light as well, this will give you sharp images if done right or fuzzy ones if done wrong.
Mic and boom $900 Sennheiser ME67/K6 - Shotgun Microphone Basic Kit This is similar to the ones we use and excellent. They come with all you need except a stand or boom. But I did like this one as well.
Neumann RSM It's only $6,000.
NOT A LOT OF CHANGE OUT OF $8000 But you need to buy all this only once every few years.
On the day costs.
Make up artist Prices vary according to location and experience. They are essential if you're shooting anything but the very basic stuff and don't mind shine on the model, zits, models make up being ghastly, etc.
Location. $80 Again prices vary. When I wrote this I was replying to a thread about amateur using their home and cheap locations. You can keep down the costs in the summer by working outdoors. A good location with a pool will cost. A villa for a week can cost $1,000s. Again this depends on where you are and you needs. We can rent an apartment here in CZ for from $200 a day.
Props, $20 a week. You will need to keep buying things like clothes and toys for the models. Some will bring there own and some will turn up in the clothes they're standing in. Budget for it. $20 a week is minimum.
Models $500 a day for solo girl. Or up to $2,000 a day for HC with anal. Every one will tell me they can get them cheaper or pay more. So again this depends on your needs and location.
How important is it to have the right kit? That depends on what you want to shoot and how well you want to do it. But even with all this you can still cock it up if you don't know how to use it and direct models.