Hardware for robot

friends iam planning to add mapping capability to my bot what are things i need to do it..

i found some links just take a look at that

accelerometer

http://dx.com/p/adxl335-3-axis-accelerometer-module-167074

here is the another link. that website says accelerometer has in built in gyro, tilt sensors

http://dx.com/p/gy-52-mpu-6050-3-axis-gyroscope-triaxial-accelerometer-6-axis-stance-tilt-module-for-arduino-148654

for encoder, iam going to use only  MOC7811 is a infrared based optical sensor and i will make black and white shades in paper.

http://probots.co.in/index.php?main_page=product_info&cPath=9&products_id=293

is there any thing more i have to see for builting it and if you have some good price link in ebay your welcome.