A few questions about wheels and lowering..

Hey guys, im looking to drop my truck a little until i can afford a couple dumps, batteries, and hose..

Im probably going to go with 3" blocks in the rear and adjusting the torsions for the front. Should I get the angled lowering blocks or the regular?

Also, i have some wheels that i had on my nissan hardbody. I know you can put maz wheels on the HB (once you grind the tabs off) So i assume i can put the nissan wheels on my maz without any problems, right? Does it matter if the stock wheels are hub-centering and the other wheels are lug-centering?

Thanks again for your help..latersjp