Any ideas about what OBD2 diagnostic tool to buy

I have a nz new 2006 swift with engine warning light on and a imported 2005 mazda premacy with engine warning light on, would like to get one tool to cover both vehicles but the jap import may have different code protocols.

difficult what swift is it suzuki have loads different engines renault and fiat as far as i recall round that years. and a primacy is probably a ford or mazdas own crap who knows. mazda is the worlds worst for diagnosing .

What should be coverd under both is global obd2 that is only emission stuff and codes must not be trusted from global obd2 unless validated with a oscilloscope and a oem capable scanner.

what ever you do dont erase the codes if you erase the codes its like whiping down a murder scene and then try to find out after who did the murder with no crime scene left to analize. As some codes wont return untill conditions are met and if a fault is preventing a readyness monitor to complete then no codes will come back . like you cant murder somone twise.

Thanks intrade, on the premacy i was hoping to be able to read the fault, clear it and remedy any issue like poked parts. On the swift i had an engine warn light come on about 90,000km ago and it ran crap, worked out it was an ignition coil pack so replaced those, sweet as, but paid $70 to have light turned off. Did it again about 10,000k later, swapped coils around again and car has run sweet since but i have had engine warn light on since.

re *5 the problem is a scanner does not tell you what parts are broken its just that sometimes the code gets set because of a broken part
it sets a code if the computer controller was unable to compensate and keep the item in its window of control. So yes a broken part also moves it outside this window but its just 1 of loads of reasons why it sets a code.
Like here a classic example you can get a code
long therm fuel therm limmit reached. So would you go to supercheap and ask for a new fueltrim for your car because the scanner told you so.
i hope you can see that this is 100% not telling you what part is faulty ,
i tells me what the likely cause could be for further testing.
also whiping codes out is a bad idea as there is a rediness monitor on now also old cars like 2000 mit 2000 onwards usually
the readiness monitor is also on the flowchart i think
if it is not able to give the ok to this monitor because of a code preventing it to set! Then any codes that would set after the readyness monitor has the green light wont come back untill the monitor conditions are met, and these codes that you now no longer have because you just whiped the codes out have been lost like whiping out half of your pictures from a murder scene.
This is the main reason why you dont go nilli willy reseting check engine light and see what comes back. that sort of stuff is what clueless morons will do and yes plenty so called professionals do this dont worry one just needs to know not to do this untill there is a time where you have to reset it and see what comes back because you saved the murder scene like sometimes a murder scene dont make sense because the scenes from 2 murders are still on the memmory.
this is the sort of reason why you would whipe it clean and if the readyness monitor dont sets again then you can figure out from the codes what to check and repair so the monitor sets again from the saved codes from before you whiped it clean.