In response to the link you posted for the lift....
Spacers are cheap way to lift your truck... As with everything else in life "you get what you pay for..."
Pros - inexpensive, better clearance for bigger tires
Cons- poor ride quality, premature spring wear (and with that many miles, it'll be exponentially worse), you won't gain any articulation, and it'll place excess wear on other parts...
My $.02... If you must have a lift, go with OME... New springs and new shocks, best of both worlds, ride and aggressive stance, not too tough on the wallet either... Pure performance lift? Take a look at Sonoran Steel 1.2 kit or Toytecs Ultimate lift, (I'm saving for the latter)... My thinking is, why spend $200 now and be satisfied for a few months, and then end up spending $1,000 more to do it right, when you could save the $200???
Note: I fully understand this is your truck, your money and your decision... I'm just offering an objective opinion, the best way to make your choice is get your hands dirty and dig in to some research, on this site, and check out
www.sonoransteel.com, a wealth of knowlege lies around here....
Happy Runnin'!!