The 247 is definitely easy to tune and can hold its tune well. Make sure to get the 247 pro. Only about 20-30 dollars more, but has more power.
The SH 28 is a beast. It revs really high, and is very fast on the track. Only problem from what I have heard is that its con rod breaks after a few gallons. But I have heard from others, if you keep it at 20% and don't run it too hot, it'll last a long time. Either engine, would be fine. If I had to do it all over again, I'd get the SH 28. It was only 129 a few weeks ago at hobby people, and when I heard and saw the engine in action, it definitely gained my respect.