I have a 5 gallon charred oak barrel (cost over $200 though) that works for cask conditioned. You don't need an engine unless you are trying to draw the bear somewhere. If you have the barrel on the stand, then leave it in the barrel for the secondary fermentation, then pour off the bear clean out the sediment, and re cask - or if you like the yeasty flavor, just use after 2nd fermentation. I use a small amount of sugar - 1/4 cup and let it sit for another few days to carbonate.
I chill mine to 55deg in my laagering fridge then gently carry keeping horizontal to the bar - and gravity pour it. It is warm (by American standards - served at around 60 deg - with a thermal blanket over it - the bar is at 68dg) and low carbonation (I don't know the exact carbonation). It tastes great to the real ale guys - the PBR drinkers don't like it - but too bad - more for the rest of us.
I run through that in 4 days - because it will oxidize - so I just make it for occasions when I know it will get used.
Keep the barrel slight tilted down - the sediment settles below the spigot. I also used gelatin when racking for the last time and have been accused of filtering- so there you go.
Ian