I think the best thing to do is order a few of the chips on that page and all the external components i need for each one so i can experiment a bit. I should probably dig out some old speakers and an old mixer too so i have better control over the volume and if something breaks it doesnt matter much.

Its a good job i know about the heat part. Normally if a chip even gets slightly warm it means ive done something wrong. This chip is obviously different and heating up is normal.

How do i put a heatsink on a chip? Is it as simple as just putting it ontop and securing it to somewhere else on the PCB to hold it on? Ive got some thermal paste for CPU heatsinks, should i put some of that on? What size heatsink should i use (roughly). Will one thats about twice the widthe of the chip, a little longer and about 1cm tall do or would i need really big ones? Theres going to be a fan or 2 in with it anyway so that should help