[JoFreak]

Well, you have to decide if you want a hardcore bashing truck or if you want a brilliant looking shelf queen.
Maybe you want to compare the prices of good aluminium suspensions and the price of the flextek suspension and see if the difference is really that big.

One thing you might want to keep in mind: if you build an all alluminium truck, you can't predict what's the most likely part to break. But it's allways going to be expensive.
If you do it like me, you have aluminium bulks which are pretty stable and stiff.
Have titanium suspension arms which are stable but can flex if you crash it.
And the plastic (RPM) axle carriers break if it gets too much, but are cheap and easy/fast to replace. Same thing for the plastic drive shafts, they keep the too hard punishment away from the hardened differentials, drivecups/outdrives and tranny.

Just my 2 €cents...