hi guys im after some advice on which amp to build ive narrowed it down to 2 ska gb300d @ 300w or a aussie amplifiers nx 500 with their psu3 60,000 mf power supply @500 w im sure their are others but my speakers are a very hard load and these are the only ones that ive found that will give me the power i need any advice especially from those who have built or heard these amps would be greatly appreciated cheers