The best wall washer for your use would be one that uses a regular light bulb(100A19) or an equivalent CFL .
The rule of thumb for attaining uniform light levels using wall washing is the distance between the fixtures should be the same as the distance off the wall.
Higher light levels on the vertical surface are attained by moving the fixtures closer to the wall, hence using more fixtures.
Most companies, like Juno, Halo, or Lightolier, have the data for mounting info on their websites.
Make sure that you use relatively light finishes on the highlighted for better refllectance.

Lightolier makes the best wall wash fixture with a 150A lamp. This is for non IC applications. 1135 Trim and 1102P1 Housing It can use a 100 or 150 A or 90 BR. This is a wall waher that really works.