Power cable upgrades, or Power conditioner?

OK here's the deal, I have a currently all digital system(ie no analog source yet), I find that the sound is fatiguing. I am looking to do both power cable upgrades, and a PS audio Power plant 300, the power cables I am looking cost about as much as the PS audio unit. I am going to do both but money doesn’t grow on trees this time of year, so I ask which one should I do first? I am not using stock power cables but I know they need to be upgraded to extrapolate the level of performance I feel is available from my system. I use a transport and a digital pre(well with in a week any how), so I will need 2 power cables and am looking into the whale elite, Pure note epsilon, NBS monitor 0 and anything else that catches my eye, or if any one has directions to make power cables from home depot available products I am all ears. I am capable enough to build power cords, but I would rather not waste time and money on something that I don’t know what I am doing , how ever if any one wants to tell me here or email a few ideas that would be great, but in the mean time which should I concentrate on the conditioner or the cables?
Thanks a lot
~Tim