Sparkle is actually pretty good, they used to have a European base in sweeden (or norway) but that got closed down a while back, I've still got a factory overclocked sparkle FX5200 some place
for a long time their low profile 9800gt and gts250 where the best and most powerful low profile cards you could get and
AFAIK they are still the most powerful low profile nvidia cards you can get, which is why they still command a rather high price.
Most of their cards are stock, they did do some card with really good aftermarket cooling too, however after they closed down their european office they've not really had much of a presence in europe,
On the the brand at hand namely Inno3D
They mainly sell stock cards except for the i-chill range who's coolers are made by various companies, Arctic cooling, Zalman or ZeroTherm (well the older card did)
Their iChill card do tend to be decent esp in respect to the after market coolers but often come with a price tag
There's a review of the 670 ichill here
http://www.hardwareheaven.com/review...onclusion.html
I think these coolers are a custom job so no idea of the OEM for them.
Full warranty of Inno3D cards should be handled by the retailer, there's a few brands like this, if you contact them they'll just tell you to contact the retailer, it should be 3 years on the ichill range, but it would be best to check with the retailer first and only get one from a retailer you trust.