Not sure what you mean by “aggressive”, but I believe you can buy a good pair of freeskates from skatepro. A friend of mine bought a pair of Powerslide Imperial from there and they’re glorious. Skatepro is definitely not cheap, though. I can’t suggest any other specialized online store (maybe inlinewarehouse?), but maybe you can try to to look for a good pair of rollerblades on the online stores of Deathlon/Sportler (if you live in EU). Anyway, I would also have a look at second-hand marketplaces. You can definitely find some good items for a lower price and at worst you’ll just have to change the wheels