Home PC, build or buy?

[peten2toms]

I am currently running 4-6 tables plus from AP, PT, PaHUD, AIM, surfing web and sometimes Camtasia all simultaneously. All on my compaq laptop which the fan never shuts off when it is on. It isnt horribly slow but I think its time for an upgrade. I currently have a 20" Samsung its the syncmaster 204b. I would like to possibly get a second monitor as well. I am looking to spend the least possible for the best results but I am not against spending a little more for the super machine I want. I am thinking somewhere from 500-1000. Basically I want it to be capable of running all those programs with no lag and more. Also I think I need a good amount of storage space for music and PT data as with ample space I will be datamining 24/7. I am leaning towards building a comp of my own with a little help from a friend or finding a site online that can build one for me. Is this the better way to go then simply buying a tower from say dell or HP? All and any suggestions are appreciated, thanks a lot.