[MattR]

By the way, you should update your profile and add your location. Sounds like you are from Europe, but a specific location helps readers.

Back to your question...
Unless your KTM 300EXC had a modified engine, the standard EC300 would be the closest in power characteristics. The KTM 300EXC had the heavier 2K-3 ignition (like the standard GG EC300). The KTM 300XC had the lighter 2K-2 ignition (like the racing GG EC300).

Just remember... you can always get the standard EC300 and upgrade items to suit your style. The money you save upfront can go towards custom valved suspension (like LTR), larger powervalve cover, different exhaust, RB-Designs head and carberator mods, etc.. The ignitions swap out easily from 2K-3 to 2K-2, so you can change them out as well. Some folks like the lighter 2K-2 ignition and add flywheel weights (7 oz, 10 oz, 14 oz, etc) depending upon conditions. It is all a matter of personal taste.

My point is... the standard EC300 can do everything the racing EC300 does and more. If it were me, I would choose the standard and save $$ for mods later on as needed. In the end, you may spend the same amount but the modified "standard" version will be set up to your personal desires.