I work pretty much exclusively on classic Minis, so the $200 hydraulic lift table I got from harbor freight works perfectly for me. My engines weigh about 350lbs, so there's plenty of capacity left over on a 1,000 lb rated table, plus it makes it pretty easy to get them out. Once the subframe is sitting on the table, I can lower the table and/or raise the lift and out she comes.
If you're working on a variety of cars/engine-transmission combos you might need to make an adjustable cradle like in the OTC ad