Ah yes, very good advice that, I was fortunate in that respect.
As a bit of advice from me, dont throw anything away, until the engine is in the van and the van is MOT'd
The radiator hose that is on the top of your engine can be used to connect to the VW radiator hose. I reccomend the reversed coolant method too, but when you do take the coolant manifold off GET SOME NEW O-RINGS!!!, mine leaked and the whole lot had to come off AGAIN.
Do not buy a halfords replacement thermostat if you decide to change it, theirs is rated at a higher temperature and has too small a hole for the water to flow through, also thier thermostat does not sit high enough in the hot water flow. TAKE CARE IF YOU TAKE THE THERMOSTAT HOUSING OFF,that part of the car gets all the crud off the road and the threads of the bolt can get blocked and it will shear off, like mine did, soak it in PlusGas and use a bit of heat (but dry the plusgas off first, its flammable!!!!) if it looks like you have to take it off.
Keep an eye out for BMW 325 85-94 fuel pumps on Ebay, I think Cavalier ones work also. Use this page as a cross reference.
http://www.fuelsystem.co.uk/otp.pdf you need FP603, have a look for all the cars with this pump, this can widen your search on ebay.
Get yourself a log on to the
http://autos.groups.yahoo.com/group/subaruvanagon/ group there are many good links with wiring diagrams, pictures of cooling systems (richards one works for me), I would recommend going for Richard's bellhousing and engine mount, If you go for the bellhousing remember to tell richard (he might ask) if the engine you have has a threaded hole for the starter, some of the subaru engines, starters bolted to the car bellhousing and some bolted to the engine.
Have a look at my bit on Subaru Exhaust in this forum.
Did you get the pilot bearing from the gearbox? If not try Richard might have one, failing that you might have to buy a clutch kit, (Clutch plate, pressure plate and pilot bearing) but you might be able to buy the bearing seperatley.
I can give you the number of the alternator belt, Unless you are planning to use the power steering pump. But it might be as easy to buy it from TSR its not very expensive.
If you need some fine pitch bolts to bolt the engine/gearbox/bellhousing, try a bike breaker, bikes sometimes have a longer bolt than a car.
Finally your engine looks a bit dull, I thinkit would benefit from some nice colour coded cam covers and inlet manifold, I happen to have some spare I will be painting/powdercoating and putting on my engine, so can get my spare ones done any colour you want.