If you're going for a 'framed, ledged and braced door' (ooh listen to me) like cali-bay used, go for the hinges he has used also. These are known as 'hooks and bands', they are much stronger than standard gate type hinges and bolt through the door as well as are screwed, much reducing the potential of the door to drop in time. A good ironmonger or timber merchant should be able to help.
Another advantage using these hinges is that if you really want to maximise width, you can bolt the frame pieces to the back of the brick piers. Looks like your frame was fixed to rear of brickwork. Recommend, drilling holes into brickwork and through timber, resin in some studding to the brickwork and fix frame with washers and nuts. JD geez. Also recommend using a bit of hardwood for frame, nothing special tho.
The hook part of the hinge can then be fixed on the side of the frame thus allowing more width. Have done this at home but not v good at getting pics on to the site. Will do if you really want a look.
If you want a cheap option for these timber doors have a look at the Magnets (yes magnet). I bought a set of these doors from them and they are pretty good quality, as long as they are hung well and well painted. They haven't moved an inch since fixing. The only down side is there are only two standard sizes, 6'6''w x6'6''h or 7'wx6'6''h. These dimensions will probably match the door you took out.You would be able to add a timber skirt to the bottom, as i said a cheap option but if done well enough should last well. Having just said all of this i've tried to look at the magnet trade website and it doesn't seem to show them, they did do these three months ago as we suggested them to a client and they were available. Myabe check your local store in person if intersetd. I only paid about £170+vat a year or so ago.
In my experience, any standard softwood garage doors, even the more expensive ones are much of a muchness, knocked out cheaply. It's all about fitting them well and looking after them.
Sheds; try and keep them off the ground (ideally 4'' min - stops rain spashing up), use a few concrete blocks laid flat levelled around, some chunky timbers across these, then shed on top, separated by a bit of damp course so moisture doesn't soak upwards.
Hope this helps
Al
, then looking on the outside there is another lintel same height as the door. Think this supports the balcony on the flat above the garage :evil: 
