Well gosh, I'm blushing! [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]
I have a simple single wall steel garage door that is no doubt much lighter than your wooden beast! I simply searched Ebay for "garage door rollers" and went from there. You'll need to measure the length of the roller shaft to determine which size you need. Normal ones for single doors and light double doors are usually 4" long. They make heavy duty ones that are 7" long, maybe even bigger. I needed 4" ones and I got the version with 11 ball bearings.
You can also search the web for garage door rollers if you need really heavy duty ones. That is what I did initially, then compared what was available to that on ebay. Ebay ended up being slightly cheaper because the deal I got included shipping all for $23.95. I think real top notch rollers can run up to $9-10 a piece.
Yes, I replaced mine by myself. The top four on each side were very simple. Just unbolt the roller mounting plate, remove it and switch out the old roller for the new. The bottom one on each side is connected to the spring/steel lifting wire mechanism, and as such, is under immense pressure. These two were more of a challenge. Since I didn't want to remove the roller mounting plate (connected to the spring/wire) so as to avoid the spring letting go (nasty!), I ended up disconnecting the door rails from the wall (one side at a time of course!). I left the upper most bolt in place and had the door lowered so the bottom roller was waist high. By disconnecting the rail from the wall, I was able to twist and pull the rail away far enough to slide the roller out from its mounting plate. Inserted the new roller and jostled the rail back into position. Reattached the door rail system. Done!
All in all, I think the rollers reduced noise by around 20-30%. Purely subjective since I don't have a dB measuring device!!!