There are many other plecos that stay small as well. Just be sure to research first and be certain of which species you plan to buy. Clown plecos are fairly common and are a good "dwarf" pleco.
IME dwarf and honey gouramis are ok together (at least mine are). I had two dwarves in the same tank, but one almost killed the other after almost a year of peaceful coexistence. The dominant one still resides in my 29 and doesn't bother the honey much at all. Each fish is different, which is why everyone has different experiences and opinions on the subject. I wouldn't mix the larger species with dwarves, with the exception of pearl gouramis and a couple of other less-common types. Honey gouramis are very peaceful and likely wouldn't be bothered much by either dwarf or pearl gouramis.