The problem with Digital SLRs is, really, to get a decent one, you are looking at some reasonable expense. Most lower end digital SLRs are just a digital compact with a few extra megapixels maybe, arranged like an SLR, with an extra screen in the eyepiece. They don't always, or often in my experience (though I admit I'm not that much of a camera nerd) have good lens support (or ANY lens support, though those two you've mentioned seem ok on that front), a flash shoe or proper aperture and shutter speed dials, but just the same shortcut settings as a compact. The only real advantage your getting is a (faked) single lens view. What you really want is essentially a film SLR with a digital back, which basically just means that it has a CCD and a memory chip, and often a preview screen and whatnot, in place of a film canister and spool. At least, that's what I want...but then again, as I said, I'm no real camera nerd, I've just picked up information and expertise along the way, as it were.
Though I gotta say, having had a little browse, that Nikon is pretty nice. How much does one of those set you back?
Edit: Jesus christ £550.
On the other hand, a cheap film SLR can be pretty much as good as the most expensive film SLR in the right hands, as a lot of what makes up the price of more expensive SLRs is basically just computerised gadgetry that makes taking pictures easier without necessarily adding that many technical options: autofocusing, computerised aperture/shutter priority options, auto-light meter, motor drive, etc. Not that this stuff can't be really handy. The camera I use is a Canon A1, which despite being a lovely, high quality piece of kit, is pretty shit for casual or action photography, because each shot has to be manually focused, and the film wound on manually between each shot. The manual focusing can also be a real bitch, because you really need a good vertical line to get the focusing crosshairs set properly. It takes me at least five seconds to set up a shot properly. But, I just fucking love film. The only real problem is that it's pretty expensive. If I'm doing a posed shot, or landscape, or studio work or something, I often carry around a cruddy little digital compact with me to preview the shots I'm going to take.
Also, I got my camera for £50 second hand. So hey.
Oh, and whilst we're on the equipment thing, the cheapest and best camera accessory you will ever, ever buy is a Sky Filter. Srsly.