Sabbath

My car is Subaru Impreza 2002. Car has had a full engine rebuild by TSL motorsport in 2004. Car has done 40000 miles since rebuild.Oil was leaking from turbo. Took it to an expert in Subarus who said that the oil return pipe on the turbo had braided and replaced it. Had a new oil change Millers 5.1 and oil filter replaced at the same time. Car was running fine before I took it in. When I picked it up I took it for a spin and noticed it was overheating more than normal. I checked the coolant and it was low. Filled it up with coolant and temp guage remained on half then going slightly hot then going back to half. Suddenly slowing down the car just stalled. I pulled up off the road and tha temp was in the high red. I waited for an hour for it to cool down and managed to get it home. I had oil in the overflow resevoir when I checked it the next day. The oil on the dipstick looks fine and there is no residue on the oil filler cap. Radiator water is rusty brown but not sure if thats due to the colour of the antifreeze or not.I havent started her up since If I got a sniff test and the HG was the problem. would it be cheaper to buy a new recon engine or to have the HG replaced? Any subaru owners out there got any advice?