Yep i contacted Technic and I will Prob be ordering his add-a-sub harness for $105. I'll save upgrading the stock amp and adding new underseat mids for a later date.
for anyone reading this thread and looking to contact Technic you can PM him here:
Technic
does anyone know if the add-a-sub harness only works with the stock amp... meaning if i switch the stock amp later down the road will i run into some troubles with this harness?