The Felpro kits are a good buy and have a pretty good rep. I used one in my car and have been happy with the results. I don't believe Subaru has a ready-made kit, so you'd have to buy each piece separately, but the parts are top-notch.
At a minimum, you will need
-head gaskets (2) note: MUST be Multi Layer Steel (MLS) gaskets or don't bother
-valve cover gaskets (including gaskets for 4 spark plugs) (2)
-camshaft gaskets (4) EDIT: should read camshaft seals (4)
highly recommended:
-intake gaskets (2)
-exhaust gaskets (2)
recommended:
-front main seal (1)
-oil pump o-ring (1)
-sealant for oil pump
I know what it means to be short of cash, but if you can swing it:
If the car is over about 150k miles and these items have never been replaced:
-everything that touches the timing belt except the camshaft sprockets and crankshaft sprocket. This would include smooth idler pulleys (2), toothed idler pulley (1), tensioner (1), and water pump (1). If the timing belt has over about 50k miles on it, replace it, too. There are some pretty good TB kits on eBay for a good price ... search the forum for recommendations on kits/sellers.
You also really need to have a machine shop check the heads for flatness and burnt valves and do the work if necessary. This is not not cheap, but is essential for a successful HG repair. If they do valve work, and probably even if they don't, you will need to adjust the valve clearances, as well.
For a first timer, I'd allow a week, including machine shop time.
Oh yeah: don't forget to change the engine oil since it's been overheated. A drain-and fill of the ATF would be a good idea as it has been over heated, too.