If you are looking for a single camera then I would look for something that does it all-in-one. I've got one off ebay that is a Foscam clone but is not weather sealed. If you can find something similar then that would work.
I decided to cover the driveway, rear of the house, side gate and also one to keep an eye on the dogs, so I went with a zoneminder solution. Basically you can set it to interface with most cameras, but I wanted decent resolution so I built my own using raspberry pi's.
Each camera costs :
Raspberry Pi : £17
http://www.amazon.co.uk/gp/product/B00Q8MM4PI/ref=ox_sc_act_title_3?ie=UTF8&psc=1&smid=A07590992ZJ1D7QSMML32
WiFi adapter : £5
http://www.amazon.co.uk/gp/product/B00EZOQFHO/ref=ox_sc_act_title_5?ie=UTF8&psc=1&smid=A1B35JSXN75T34
Memory card (for operating system):£4.60
http://www.amazon.co.uk/gp/product/B00MBTKT6S/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A3P5ROKL5A1OLE
Camera : £19 (there is an IR and non-IR one, the IR one has the IR filter removed, better for low light or with an IR illuminator, but washes out the colour. For security the IR one is best.
http://www.amazon.co.uk/gp/product/B00G9AZ79O?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00
Total: £45 (ish)
It's a bit more than a foscam clone but is 5 Megapixel and allows a lot more flexibility. Keep in mind on top of that price you need some kind of housing. I put mind in one of these:
http://www.ebay.co.uk/itm/High-Quality-Fake-Dummy-CCTV-Security-Camera-Flashing-LED-Indoor-Outdoor-Black-/371362344556?pt=LH_DefaultDomain_3&hash=item5676ebae6c
The advantage of this solution is you can add extra cameras to it and it records centrally (you could keep the server in the attic or garage). I can connect using my phone and check on any of the cameras and the only limit on how much it records is the hard drive capacity in my server.
People often say WiFi is unreliable, but I have just looked at the logs for all my cameras and they haven't missed a frame in the 7 days it's set to record (probably none prior to that, but that's the limit of the logs).
One thing to keep in mind, in zoneminder you can set it to motion detect. In my experience this does not work very well outdoors. Every time a cloud goes over the contrast changes and it triggers. I just set mind to record all the time and might rig up some other notification for motion detection.
The other advantage of recording centrally is a potential burglar can't just rip the cam off the wall and take the memory card (well, they can destroy the cam, but if they forgot to cover their face or noticed too late then the recording is already elsewhere)
Just re-read the OP's question... sorry, still half asleep... this solution may be a bit over the top for a garden cam, but you could still use the raspberry pi for it (no pan and tilt though) and set it to record locally (using motionpie), then you could add the rest later if you wanted more cameras. If you were using it for wildlife then the 5MP sensor is pretty good (just prob better to use the non-IR version). Will leave all this gubbins in the post in case it is useful for anyone looking for CCTV
