Canon T4i - Accessories

Dear Friends,

Am planning to buy Canon T4i as my first DSLR camera and am looking forward for your valuable guidance.

Is there any major improvement in Auto focus (still photography) and speed compared to T3i? Am not sure what are the upgrade features with new Digic 5 processor as well. Overall i need to know the value of upgrade from T3i to T4i considering extra cost I don't care much about video, so am more concerned about the new value added features T4i would bring compared to T3i.

Major reason for going towards T4i is its all new 18-135mm STM kit lens. Where i can just carry around 1 lens for most of my needs. Please provide your inputs even here comparing it against combination of T3i + 15-85mm USM IS lens ($650). Since cost wise both options would turn up the same.

If indeed i go with T4i, please suggest me additional accessories i would need to buy (cost effective since i am already stretching my budget for T4i):

• Waterproof carry bag for DSLR (which fits Body + 2 lens at the most)
• Lens Hood while shooting outdoors, since i go out on trips and have to take pictures of people.
• UV filter - 72mm
• SDHC card - 16GB - Sandisk class 10?

Please provide me with links if you are aware of any good deals

Thanks a lot!