Front seat options for e36 sedan?

[RRRR]

HiI found e46 m3 seats (electric) and e39 mtech/sport seats (electronic - do they come in manual?) and will like to know if:1) either option can fit nicely into my e36 sedan?2) Which needs to mod the seat railings?3) Was told the e46 m3 seats weighs 70kgs each? (coz of the elctronics) - true?4) What is the weight of 1 x e39 mtech/sports seat? 5) Anyone has pic of e39 mtech/sports seat? Thanks