

It all depends on the way you want to use the name and on the way you present the name to everyone else(logo).
If you use it to provide different services than "HEPOO" does then you are ok.
If you want to provide the same services you may be facing trouble even if you present a totally different logo, just beacause this is a fictionary word and not a dictionary one.
In case it was a dictionary word you would be ok to go for "HEPPOS" even for providing the same services, but you would have to present a very different logo so that there would be no confusion to the public.
Feel free to pm if you have any questions.
