I have a 91 toyota mr2 which need to change the clutch line from clutch master cylinder to slave cylinder. Where can i get the aftermarket parts? or i can just replace the rusty part, but where can i get the connector that connect to slave cylinder? (i brought the wrong connector from local auto shop, 1/4 SAE standard, i should get Matrix)

I hate this particular project. Yes, you need metric ends at least. The problem of course is that auto parts stores don't carry long lines with metric ends. I ended up getting a "pipe flaring tool" so that I could put my own metric ends on the standard pipe. I then bought a short 7" metric line from a parts store, and cut it to use the ends on new standard size line. You will either want to get a nice one on loan from a friend or take the car to a shop. The cheap $30 tool I bought at one of the big auto parts stores didn't even work correctly out of the box. Ended up buying a $150-200 one that works great! Still a lot of work and expense if you are doing it yourself. The line is hard to get to once it gets up to the front of the car, so cutting out the bad rusty part and putting ends on is the easier do-it-yourself project - if you have the brake line flare tool. I would take it to a shop. Good luck!