asking for help building a custom sub

[MACnonsence6]

so i have 3 custom subwoofer ideas im my head one i have the motor for the pair ill be getting motors for the end of the month.

i have a jlw713 motor that id like to build using a coil from psi and a tc,ti 12 basket with a sundown x or similar cone cut to work with the coil. my question is how do ik what spiders or how many to use. i plan to use the spider spacer and i was thinking 2 on top and 2 under it. prolly these cut to fit.

http://www.ebay.com/itm/10-x-3-subwoofer-spider-damper-SP1030S-/130985954850?pt=LH_DefaultDomain_0&hash=item1e7f5f0e22

looking for advice on that proposed set up. then my next plan of action is a pair of re destroyer 12s using the same baskets. and prolly the same cones not sure if that would be the best for this set up though, thats why im here asking for opinions and advice. im pretty set on building these my self as a pride and learning thing. my main issue is spiders how do uk if you have enough to little and i feel like bottoming out, coil wobble,rub and staying linear become issues. thats why i wana use the spider spacer for the jl build i feel like having multiple spider locations on the coil with a high xmax motor like that should do a good job keeping it linear.

wana turn the destroyer 12s into 4k rms monsters looking for help and advice to acomplish these goals