I recently had to decide which Dob I wanted. I had already ruled out the other options because Dob is nice and cheap for the amount of aperture.
I had looked through a 12 inch and it was very impressive, but I found it would not fit into my car, so I chose a 10 inch, because I wanted to take it away from the light pollution in the city.
I didnt want a collapsible scope because I thought they might be hard to collimate, but I have since found that is not the case. However even a 12 inch collapsable tube scope is still quite heavy to get into and out of my car. Depends on your car and your strength, you might want to go for either 10 inch or 12 inch.
If you can get to any of the Astronomy Society viewing nights (see
http://www.assa.org.au ) then you might be able to compare weights and viewing. I have since had side-by-side comparisons of my 10 inch and another members 12 inch and they are both good, but the 12 inch is noticeably clearer on the faint objects.
With the Dob mounts, any brand is pretty much the same. I have a sky-watcher, but I think the Meade equivalent is comparable. ( I may get flamed for this - but it is my opinion). The other styles of mounts do have more difference in quality between different brands.
If you really want to start with Photography in mind, then you are talking about a very different mount and a Dob is less suitable. The astronomy society has some very good astro photographers who can give you a very good idea of what might suit you.
The Go-To feature is good for locating objects, but takes a little more time to set up each time. Sometimes I wish I had one and sometimes I am glad that I dont - since I am slowly learing where things are. I preferred to save the money on the Go-To and spend it on the bigger scope.
The astronomy society is quite friendly and you will find members who can assist with almost any question you have and get you a lot of information before you spend all your cash. You can also get some second-hand scopes which are pre-loved but may give you better value.
This site is also full of friendly people with even more information, but actually seeing different scopes side-by-side is valuable.
Hope this all helps - it is a big and interesting hobby and lots of different people and different opinions - You got to work out the best balance for what you want from the hobby.