Des, i think Gill means spot ons at the same time
Cosmic, you can use frontline instead of advantage. Your vet said stronghold was better because it does roundworm/ear mites but your worming monthly so dont need that extra cover.
Frontline costs £15 for 6 and lasts 5 weeks, vetuk is cheapest and as michelle says there are several rescues on here who earn 5% if you click through their links.
Panacur paste, fine for small kittens who are easy to restrain but i would think its about half a tube for a 4kg adult.....
It also doesnt treat the most common type of tapeworm.
This link shows you the method for tableting
http://www.fabcats.org/worming.html i find for a difficult cat its easier to sit on them
eg kneel down with the cat between your knees.
If they have a extra special fav treat then use that for tablets, my lots is raw steak with the tablet slotted inside!
Oh the other spot ons you could use is advocate for fleas/round worm and droncit for the tapeworm. May be cheaper that way?