A 105 is going to have a better peak lift characteristic than a LS6 spring, but it will have a higher chance of floating.
105s will also be easier on a stock timing chain, but LS6 springs are pretty easy as well (and I will soon prove that 130s on a stock chain work fine as well.)
I have installed 130's onto the intake side of every supercharged cam install I have done in the last few years, and LS6 springs on the exhaust, stock timing chains in all of them. The only exception was a local that wanted a stupid low idle (against my advice) and we installed a double roller and a full set of LS6's (yes they float) on a NIC.
