Just about to put mine in, with a 2.5" inlet intercooler.

2x2.5" silicon 90 degrees
1x2.75" to 2.5" reducer 90 degrees
1x2.5" x 90" Al bend
2x 2.5" bit of Al tube
1x2.5" straight Si joiner
1 x AFM adaper to 3" pod

I think that's about it - still waiting for some of it to arrive to determine if I've screwed it up.

Cost around $250 for all the stuff,

There seems to be 2 or 3 decent shops on ebay - most located in QLD it seems. Although all comes from China.