I can't get the link to work to view the parts, but....anything is possible. Ultimately it all comes down to goals, ability, and money. To put it in simpler terms; you either pay for the knowledge, buy the kit, and install it, or you take the time to learn all the intricacies and interdependancies of suspension design and fabricate you own. If you can rattle off the impact that anti-dive will have on caster gain, or understand how the roll center placement will change the moment lever arm layout, then you've got a good start.
For that matter, what is prevent someone from retrofitting Nascar spec parts to a mopar and creating a coil spring and truck arm system? Only time, money and desire.
What is the goal, what is the budget, what are the rules (if any)? Combine that with what do you know, how good are your skills, and how much time do you have? Answer those questions honestly and you can come up with an answer pretty quickley. For some of us, dumping $3k into a pre-fabbed suspension is well worth the money, time and effort. For some of us, $3k is a hella lotta money that can be spent on other systems. Some of us can make the stock stuff run better than a pre-fabed unit or a custom built install and do it for under a grand. The point is each situation is differnt and dependant upon our own particular circumstances.
Me, I'm jsut waiting for someone to tool up for some decent forged 2" drop spindles for Mopars that are under $300 a pair.