Well $5000 is quite a bit.
There are a few ways you could go about it.
Primes 'r' Us - mostly using prime lenses, great big apertures, sharp as a pin, but you'll be zooming with your feet.
Zooms 'r' Us - Mostly using zoom lenses, great for changing perspective or getting closer without "getting closer" but apertures get a lot lower.
You don't have to get everything in my suggestion below but eventually its what you would want to have at least.
2 x Canon 30D - The 30D is still a great camera, and going cheap now the 40D is out. Doesn't have much to loose against the 40D apart from the live view. The 8MP is more than enough even when cropping down to 5 or 6MP it can still produce great 8x10 or 8x12 prints.
1 x Canon 17-40mm F/4L - Groupshots outdoors or indoors with or without flash and full length to shoulder height portraits.
1 x Sigma 20mm F/1.8 EX DG - Indoor/Low Light group shots or half lengh portraits with the background blurred
1 x Canon 50mm F/1.4 USM - Indoor/Outdoors half length/shoulder Portraits, no flash.
1 x Canon 85mm F/1.8 USM - Indoor/Outdoor shoulder/head shot Portraits, no flash.
1 x Canon 70-200mm F/2.8L - Indoor/Outdoor Shoulder/head shot Portraits, with or without flash.
2 x Canon 580EXII - One as master, one as slave to ensure even lighting.
Thats about it personally, perhaps an even wider angle lens, and a logner telephoto, but to start with the 17-200 range is fine i would have thought, any wider and distortion starts to creep in, and longer lenses than 200 start to burn a serious hole in your pocket if you want them with IS/Large Apertures or, both!
Canon EOS 5DmkII + BG-E6 + Canon EOS 40D + BG-E2N + Canon EOS 33
Canon 17-40 F/4L
USM + Canon 24-70 F/2.8L
USM + Canon 28mm F/1.8 USM + Canon 70-200 F/2.8L
USM IS + Canon 85mm F/1.8 USM
Canon Speedlite 580EX II + Canon Speedlite 540EZ + 2 x Nikon SB-80DX
Cactus V2s Wireless Trigger - 5 x
Cactus V2s Wireless Reciever