I have used the cardinal 102 which has 20lb power pro on it at the lake near wichita falls, it has caught 3 10 lb catfish with no problem, it can hold 130 yds of 8 lb mono / 30 lb power pro---the diawa 7.1 sh can hold 150 yds of 12 lb mono or 50 lb power pro. My question is, since these are not big reels will it damage them putting this large of power pro on them? I had thought that either 20 or 30 lb power pro on each would be O.K., putting 75 yds on each one, would this be O.K. also what size mono backing should I use?, if I use 8 lb mono will that still provide strength for catching a big cat?, or does the mono weight have anything to do with the power pros strength? I read that 50 to 75 yds was usually enough braided line for catfishing?

I use about 110-120 yds 35 lb braid Cabelas yellow Ripcord on my Mitchell 300 and Penn Fierce II reels both 4000 size and have never had any issues with either one. Both of these reels will hold any fish the the line can handle. Don't see why there would be a problem with the Garcias or Diawas.

This question is a little more about preference. You can theoretically catch an 80lbs cat on 10lbs test line if you work the drag properly. The line will never break if the fish pulls drag out before the line reaches its breaking point. With that being said, if the fish pulls so much line out that you reach the end of the line it will snap where it is tied to the spool of the reel. Most people probably try and find a happy medium.

I have 150 yards of 50lbs braid on my reels. If I were a wealthy man, I would have 300 yards of 80lbs braid on a bigger reel... just in case I ever hook into a MONSTER.

Catfish aren't Bull Reds. I've never had one rip off more than 20-30 yards off in a single run. On catfish tackle, mind you.

I would just rather be safe than sorry.