I'd rather buy the Spa Cycles own brand cranks - available in lots of lengths and a total steal at £25. I've bought several over the years, the quality is excellent. Add a narrow-wide chainring from Superstar Components in a nice fruity colour.
The finish on them is really good, can't recommend them highly enough. Bearing in mind the problems people get with external BB setups being tetchy on tolerancing I'd steer clear of the Chinese stuff.