Replacing carpet Options

[conus00]

Hi guys,
first of all please bear with me as I am complete "Celica noob". Until now I have owned two second gen Probes I have been tinkering with. My gf's Dad got her a winter beater - 1994 ST coupe which she no longer needs so I will probably end up with the car. The car is mechanically sound, he actually replaced the engine with 1.6L(?) Corolla engine but the interior is in really bad shape. We had to throw away rear seats (they were completely molded) and cover the torn front seats with seat covers. The worst (visible) part of the interior righ now is the tan carpet which desperately needs to be replaced.
As I said before I have never worked on any Toyotas so here is my question: how hard is it and also should I go with aftermarket replacement (worried about fitting) or should I rather look for OEM replacement?
There is used black one in decent shape listed on Ebay right now for 80 bucks delivered. Is it too much?
Also, I have looked at the interior: I have to remove both seats, center console, rear trim, door sills and small pieces of front kick panels. Do I have to remove dashboard as well?

Last question: (not exactly about carpet but related to) Does anybody make brackets for aftermarket seats?
Thanks!

[bmj67]

as far as I know you just have to remove the seats, the center console, the door sills and the kick panels to replace the carpets.