I'm building in Thailand with limited local resouces and even less knowledge. 220v here.
I want to run a min. 30m of rgb 5050 using a dimmer for the run and one power source if possible. 

(I could change to a single color (warm white) if the soulition is simplier.)

Online answers from Chinese suppliers vary from a big list of supplies to one that said I only needed 30a transformer.

One answer on this site suggested using a computer power source (say 450w) to get the 12v and supply the whole run, but I'm concerned about frying the first strips.

Anyone that point me in the right direction with required products or schematics would be appreciated.

Thanks