Writer's Pre-emptive Strike: I'm about to write blasphemy. If you are in any way enthusiastic about Real Ale, look away. You have been warned.
The tricky business about proper cask ale isn't the dispense method, it's getting the oxidation right. Dispense from a standard keg is pretty easy--all you really have to do is smash a beer with low carbonation through a small orifice at high pressure. Don't crash the ale, just keg it at your finishing temp. At this point, hit it with 20psi of gas, then toss it in the fridge. Hit it with a further 15psi the following morning, then let it sit for a few days. When you want to dispense, put your keg back on the gas and give it a good shot of gas, then turn off the gas. Next, half cock your tap and pour *slowly.* I'm cheap and I use cobra heads, I don't know if this technique works with proper faucets. Don't be afraid to take a bit of gas off the beer with the PRV if you're shooting foam. When your session is over, use the pressure relief valve to dump the high pressure dispensing gas to avoid further carbonation. It will take some practice, but I have learned how to get a pint that looks and feels like something that has been through a beer engine. Blasphemy!!!
But the tricky part is the oxidation. I gave up trying to do forced oxidation on my beers a long time ago. My taste has evolved and I have a hard time convincing myself that oxidation is a good flavor. My final technique utilized a closed transfer followed by opening the keg's lid under a Star-San soaked paper towel and letting it sit for a few minutes to let oxygen mingle with the CO2-dense headspace. At that point, I would close the keg, hit it with 20psi (no purging), and follow the process outlined above.
At the end of the day, I've come to terms with the notion that proper cask ale is something that you get at a tavern that specializes in cask ale and has enough traffic to ensure that it can pour a decent pint. Put differently, it's something to be enjoyed at the perfect place, at the perfect time.
My fridge is neither of those things. It took me a lot of years to learn to be okay with that.
Anyway, that's about all I know about this.