The bikes you're describing still arent designed to handle 2-3 foot drops consistently at your weight. If you're going to ride DH, you may just want to get a little bit beefier hardtail and go it that way, unless you want to build a real DH bike.
Personally, i think if you can afford a bike like a Blur, it'd be a shame to equip it with a bunch of old used parts. A really nice used Full Suspension bike could be purchased for the same price...and youd not destroy it....but hey........its your money.