I got my whole set from RiffRaff. I think they sell just the spider to intake boots

 

Got mine from silicone intakes.com

 

Race Part Solutions out of FL.

 

Turbo Outlet Y-Pipe to Intake Manifold Boot, Early 99 (used for 99+ Intercooler Retrofits)
(Ford) F81Z-6C640-FA
(International) 1821764C1

See if you can get the International ones as they were about $15 each (and Ford wants a mint for them) a few years ago. Cheers!

 

I've got those IH boots (1821764C1) here. They are quite a bit less than the Ford one (F81Z-6C640-FA). I guess it depends on who makes what for who.
Anywho, current $ is 18 vs 50.

 

Diesel site makes some nice, high quality ones.
I used them on my inter cooler set up.

 

I got mine from RiffRaff. They are quality boots and are priced decent. You can buy them individually as well.