Well I'm picking up my injectors today from shorty, I don't need the pump so it is for sale. 60 takes it.
http://aplusperformance.com/walbro/walbro-fuel-pumpinstall-kit/400791/i-217511.aspx You'll need that to put it into your Subaru. Still, for under 90 bucks total, this is a great deal.
i found out when i put mine in, the stock plug, plugs right into the wolboro! no need for an install kit.
You need the rubber grommet that cushions the bottom of the pump from the kit. And the filter bag from the stock pump sometimes doesn't fit, and you should change that out anyway since you're in there.
The kit includes the rubber shock isolator. So, no. Unless you come up with some sort of custom mount to drop in.
I installed my fuel pump without the install kit, nor did I order it and everything worked fine. I reused everything from my stocker and it fitted good.
I believe 05+ came with the fuel filter into the system. I know mine did. I was told I can squeeze the pump into there tightly or cut the end of the filter's nipple off to fit it in (which I did). And I reused everything from the harness to the sock. It's just a pain to remove the sock off the stocker (the c-clip holding the sock is the hard part actually).