IB question

[89ChevyDriver]

i know when doing and IB in your door seal the inner from outer shell.... whats the best thing to use? as well as i attached a pic the biggest hole has my bars for locks and handle running through it i simply cant put something over it whats the best way to go about it?

also having a hard time deciding between using P1 8" subs or rockford pro audio 8".... mostly due to my lack of understand what instrument and noise is produced at what frequency i guess? i know i like lower note, pure bass, drums, bass guitar... thats why im leaning towards the subs....both are about the same price and i want to run all RF gear any suggestions? ive installed subs highs and mids and made noise but id like this go around to sound as good as it can for what it is

currently running a pioneer flip out with an 8 band eq unsure of model number at this second and T1 components i plan to get an older 600x4 running the t1s @4 and the subs or mids @2 on the back two channels

[Florida Rep]

Best way is to use a aluminium plate to cover the holes. Second alternative is ABS plate & last route is a big piece of damping