Page 1 of Canon Pixma IP4300 - Chipped Cartridges and/or refill?

I`ve just bought an Ip4300 to replace an old epson 580 that finally broke. I obviously didn`t do my homework on ink cartridges as I can`t find any chipped cartridges from third party suppliers? Has anyone used one of the cartridges where you cut the chip off your OEM cartridge? Does it work? How do you know when it is empty (as you have to over ride level indication)?
Same question for refills - I used to get in a right mess on an HP and vowed never again!
Finally who has the cheapest OEM? I can find them on Amazon at £7 to £8 depending on colour.
Build, speed and print quality are great by the way.