Standard ford head units (which i am assuming your still running mate) are pre-amped, 130 watts would be no problem, the reason the stock speakers blew is because the head unit is too powerful for them, front audio in a car is hardly ever run by a dedicated amp like 6x9's and bass drivers in hardcore installs
Ford use unbranded SPLX speakers (el cheapo brand) paper cones etc, your car will in fact take ANY 13 cm speaker (designed for car audio obviously), pioneer ent the best, and thats certainly not the best price, Vibe are all the rage at the minute, try these:
Vibe Slick 50 v2 5" Inch 13cm 2 Way 150w Car Speakers on eBay (end time 12-Mar-10 17:09:58 GMT)
I am 99% sure they will fit (the mounts are universally in the same place on all speakers of the same diameter, sometimes the speaker is slightly deeper than the door panel can take but from memory, fiesta doors are hunka chunka with loads of room).
These have built in splitter and 'tweeters' so sound quality will be far superior, i'll buy you a new set if you blow them!
OK to fit em or need to know how?