Hi Hcker2000,
well, I assume that with film few users would really use the 5 FPS because of cost - unless they really need it (e.g. professional sports shooters).
On a digital body, everybody can do it, as it does not cost anything 
But still, it is my firm conviction that you get better results with taking a single shot and making that single shot work. Of course, with people, that single shot can often be flawed if the person just speaks, yawns or looks in another way awkward ... then it might make sense to have more than one shot to choose from.
Most things were said ... you should be able to use your lenses on all Canon dSLRs, but maybe don't expect miracles. A lens that was perfectly ok for printing 3x5 pictures still is ok for that ... but with digital, you look at the images on your screen at high magnifications, which would be akin to plowing them up to 20"x30" posters in the old days. Not many people did that, and those who did had to use their equipment in the right way. With small prints, you won't see much of a problem.
With the 1.6x crop, IMO it makes a lot of sense to get any camera at least with the 18-55 'kit lens' (most cost-effective way to get a half decent wide angle lens for 1.6x crop), or look at all the wider options (e.g. 10-22 etc.)
Other than that, my suggestions would be
- get the 400D (or 350D if finances are tight) if you are just starting out, they are great cameras
- maybe check out the 20D (used) or 30D ... they do not offer much more from the image quality standpoint, but are nicer to the touch/more robust/have a few features more that might be important
- 5D ... IMO a very good camera for those willing and able to pay $ 1,500 more to get a marginal improvement in image quality over the 30D. Now many might contradict me here, however, I have seen great images taken with very cheap gear and really crappy images taken with the most expensive. The difference is really more the photographer behind the camera than the tool itself. IMO not necessary for a beginner, unless he's thinking what would be most suitable to put in the glove compartment of his Mercedes 500 S 
- more important than the camera ... good lenses. Your 50/1.8 is definitely a lens that has a potential to give you very good images on a digital SLR. The zooms a bit less so, but they should give you decent images, if you use them within their limitations (maybe stop them down to f/8 ) - or if your requirements are small prints and web images. Nothing wrong with that, but if you look at images taken with cheap consumer zooms (regardless whether they are Tamron, Sigma, Canon, Tokina) at 100% magnification, chances are that you will not be 100% happy. Other than that, use what you have (plus the 18-55 kit lens) to learn what you would like to have in your new digital world and make a decision whether to upgrade or not once you have a bit of experience.
Best regards,
Andy