cameras?

Any camera buffs reading this? I need some advice. It might be time to start thinking about moving up in the world of cameras. What I have (it's now 5 years old I think) is a Nikon Coolpix 5700, 5 megapixels. I do love this camera, it's easy to pack around and great for most things (and really excels at macro photography). But when it comes to telephoto, it sucks. Images are not sharp, and it just doesn't have the range that I had with the old Nikon SLR and the mondo huge telephoto lens. The Coolpix does not have any ability to continually focus while shooting photos, so if the subject is in motion it's not going to work well. And I miss the ability to manually zoom and focus by adjusting the lens.

So basically what I want is a digital SLR that has the same look at feel as my old film SLR, only shoots digitally instead of on film. I want manual focus as an option, I want continuous focus while shooting, and most importantly it MUST be compatible with my old lenses:
Tamron F3.8-5.6 28-200mm
Tamron F5.6 200-400mm

These are old lenses, 10+ years. But they are good. The downside is they are enormously heavy. So I know this means getting back into the "heavy camera" world again. Ugh. I'm guessing newer versions would be just as pricey as these were though.

There have been a lot of times when I've needed more telephoto power than I can get with the coolpix, but haven't wanted to shoot film. I'm going to run into that problem again next month (I hear there's some wildlife in Yellowstone, I'm going to want to take a zillion photos, do I really want to shoot film again?? I could, I could just pack along the Nikon N6006 and a whole bunch of film, it's definitely an option.)

Does what I want actually exist? (at a price that won't kill me?)