I did a heater core on my 1993 2.0L turbo UK RHD (I see yours isnt). It was a bit of a swine, but using the FAQ its not too difficult. I really needed to keep using the vehicle for work so I just linked out the heater pipework in the engine bay where it goes into the bulkhead with a bit of 15mm copper pipe I had lying around and still keep it in the car just in case. All depends where you live I suppose but I think it was late winter/early spring for me so not too bad. Take lots of pics with your phone as you go when you replace the core, I remember from the faq that a couple of the screws on the box that its in are a bit difficult to get too and remember where you pulled the various vacuum hoses off from. Once youve made a start it wont seem so bad, but there is a lot of upside down in the footwell type action ahead so hoover it out first. I didnt worry too much about which one to buy, but probably plastic bad, metal good. Remember its just a small radiator in a box and would probably work if you taped it under the dash. Good luck and its so satisfying when it all works again and the carpet is dry!