Just to say that I wouldnt advise anyone to do that, what might work for one, won't work for everyone. HEb's or HEa's for that matter are not just about calories and it is not something Slimming World advise. What would be the point of slimming world selecting all the healthy extras, if we just select and make up our own.
Slimming World select the healthy extra's very carefully by looking at a number of factors, i.e. FULL nutritional information and ingredients.
I suppose it depends on how 100% on plan you want to be. Fair enough if it works for you, but you have to be careful when offering out suggestions that are not following the plan.