First of all, words that are high in frequency are far less likely to result in speech errors. There, you can have words that are uncommon, but that are pronounced in the same way as more common words. We already said that the outcome is more likely to make a new word than would be expected by chance. There have been several studies that attempted to find such an effect, but they have generally been unsuccessful. It seems that the only effect on outcomes is that they are likely to be words, rather than nonwords.
Frequency has less of an effect.
Rather, the type of word really seems to matter only in terms of the likelihood of making a slip in the first place. Mike Vitevitch did a study on malopropisms. He found that malapropisms tend to have sparser neighborhoods than control words of equal length. A neighborhood consists of a group of similar sounding words that are confusable with one another. It would also include words like bay and ache, which are one sound shorter, and words like brake, which is one sound longer.