what is the good DSLR camera to buy?

Unfortunately, at this point in time, there are no full-frame DSLR cameras for $1,200.00 unless you buy used. Even then you'll probably have to settle for a much older model.

Here are several models I think worthy of your consideration with prices from B&H:

Pentax K-50 w/18-135mm zoom, $1,096.00 This camera and lens are Weather Resistant (WR) which means they are safe to use in the rain or in very dusty conditions. This does not mean you can take the K-50 swimming. It isn't Waterproof, just resistant.

Review: http://www.imaging-resource.com/PRODS/pentax-k50/p...

Sony A77 w/18-135mm zoom, $1,198.00 after a $200.00 'Instant Savings' from B&H that ends 9-28.

Review: http://www.imaging-resource.com/PRODS/AA77/AA77A.H...

Nikon D7000 w/18-105mm zoom, $996.95 after a $300.00 'Instant Savings' from B&H that ends 9-28. This is the lowest level Nikon DSLR with a focusing motor in the camera body. What this means is that the older, less expensive Nikon AF lenses will auto focus on it. Lower models such as the D5200, D3200 require using the more expensive Nikon AF-S lenses if you want auto focus.

Review: http://www.imaging-resource.com/PRODS/D7000/D7000A...

Note that only the Pentax K-50 is Weather Resistant. With it you can be out shooting in the rain if you wish while the Sony A77 and Nikon D7000 owners are seeking shelter.

The K-50 and A77 both have a focusing motor in the camera body as well as their versions of Image Stabilization.

The K-50 can use any manual focus or auto focus lens ever made in the "K" lens mount that dates back to 1975.

The A77 can use any legacy Minolta Maxxum AF lens made since 1985.

B&H: http://www.bhphotovideo.com/

Edwin has given you a throughly sensible answer.

You can't really mix and match cameras with APS-C sensors with those that have 35mm sensors unless all your lenses are suitable for the 35mm format and and simply crop to the centre on APS-C.

Also with full frame you need very large and expensive telephoto lenses.

Sony A99 could be where to look if you insist on 35mm sensor... all the old Minolta AF lenses will fit and work well.

Canon 70D or Sony A77? Well, the A77 is a very capable camera with a nice OLED electronic viewfinder, but who knows what Sony are planning to at present with their seemingly obvious move towards mirror-free designs. They have just introduced the A3000 which is like a NEX in the shape of an SLR body. See: http://www.dpreview.com/products/sony/slrs/sony_a3...

Does this mean they are soon to discontinue development using the Alpha Mount?

Yet again Canon looks like the safer choice.

In the first place, only professionals or advanced ameteurs buy a camera body by itself. The reason is simple the body represents the professional's second camera and there is no point in having two 18-55mm lenses. You do not buy into the DSLR system with the intention of using only one lens. Since you admit that your knowledge of DSLR's is limited there is no reason to demand a full frame sensor.This only increases your cost quite a bit. Yes it is better, and driving a sports car is better for you and me, but we don't need that kind of performance in a car or for that matter a camera. You can still make 11x14's and 16x20's all day long from your DSLR. If you are employed by the magazine industry as a top photographer, then yes you should make sure you have a full frame camera (sensor). My advice is to get your feet wet in a DSLR. Basically the way you are thinking you should really start your "foundation" in photography with a quality "bridge" camera ($200-to-$400). This type camera has one zoom lens that gives you all formats from wide angle to telephoto plus macro for close-ups of small things.

Back to your DSLR, you really have not given me the reason you like one over another. That reason should be how comfortable you feel with the camera, sighting through the camera, locating the dials and controls of the camera. It is for that reason that I moved from owning Canon SLR film cameras all my life to Pentax DSLR. Your reasoning on cameras is good tech wise,but you need to move into personal feelings, not what we like.

The 70D is not Full Frame, nothing is FF at $1500. Why exactly do you want to go FF as a start? All of the non-FF cameras are amazing as well, and cheaper, I think you should start with canon 60D/70D or Nikon D7000 and then some time later see if FF is really what you need. But millions of photographers use APS-C sensors and it's all good.

Here's a DSLR Buying Guide - http://www.smashingcamera.com/which-dslr-camera-to...