For a lot of distance-related shooting, a higher megapixel rating is nice to have so that you can crop at 100% and retain a good sized photo. Of course, cropping at 100% necessitates that your sensor must be of high quality.
One of the reasons I went with a Sony Alpha series camera and will stick to them. Any "A" mount lens that auto-focuses will have the benefit of having the IS built into the body. I have 25 year old lenses I used for my Minolta Maxxum film bodies that are great lenses, and now have the added advantage of the in body IS system on my Sony's.
^^ This ^^
Some of those old Minolta lenses can be found really cheap around here and they are still in mint condition.
Remember, particularly with 35mm the lens IS the camera. Nikkor lenses are of the highest quality, IMO. A $150 Nikormat body and good used high-speed fixed lens is the direction I would be looking at for a manual 35mm.
You will pay for it, lots more for it, but go with a high-speed lens, not less than a f2.8. I have little experience with the D series Nikons but if I'm mistaken you can use a used older fixed lens on them. You may find a fixed 300mm 2.8 for around $800. Mount that up to a D90 and a good monopod and you'll have a decent set up for less than $2K.
Both Nikon and Canon entry level DSLRs are great for long range photography, but I would suggest you play with them before purchase. Most camera shops will let you evaluate in store. I have a Canon T2i, because of the low cost, and compatibility with my existing Canon lens.
A good tripod (I prefer Bogan personally) is a must, and consider a good head mount as well. Consider if you plan to travel, because lightweight tripods tend to cost a lot more, but really make a difference in portability. A good tripod head will give you a lot of flexibility to ensure you get the shot you want without a lot of fuss. You might even want to sandbag the tripod to ensure no movement during the shot.
Don't cheap out on the lens. Especially for long range photography, the quality of the glass, smooth focus and even image stabilization will go a long way to preventing frustration. Turn off autofocus features when shooting long. I have ruined a lot of shots when a bird or something flies into focus and sends the camera into a new focus.
The forecasted water spouts got me thinking about long range photography again.. I live on the lake and often see the large ore ships, and other interesting things but they are usually a mile or two away and way out of range of my outdated 5 megapixel Nikon.
So what kind of entry level setup would you recommend?
I would prefer digital but certainly wouldn't rule out 35mm.
I'm guessing a tri-pod, telephoto lens and camera, anything else?
The tri-pod will assure there is no movement/blur in your photos.....and, of course, I'm not in the price range of cameras that are guarenteed to do the job you're contemplating, but I am still using a Canon Powershot S2 IS which has a 12 x optical zoom and 4 x digital zoom which is an overall 48 x zoom and 5.0 mega pixels. I use it for photographing everything and even record the special music in church. Does all I need it for right now, but would like to have the other type cameras.....which definitely take beautiful photos. The fawn in my avatar is one of my photos.