Good question, it's not that easy to find existing words that match that well. If you asked me to do this I'd probably try making up fake words that in my mind,

Good question, it's not that easy to find existing words that match that well. If you asked me to do this I'd probably try making up fake words that in my mind, at least would sound closer (and that is also non-trivial given the weirdness of English pronunciation). Also, I'm no linguist, my only credentials here are being bilingual, albeit with an accent (lived in the US from 0 to 8 years old and the past ten years, and a south-american country from 8 up to my 20s). So I lack the terminology to describe what things sound like. That said - Cola, I think is fine. The "o" in toes is pretty different from the one in adios. I'd say that maybe it rhymes with "adipose" or "lactose", except the accent goes on the last syllable. Gracias, isn't too bad, but maybe I'd say "fascias" (admittedly a relatively obscure word). Manana is obviously wrong - here I'd just make up something like "man-nyah-nah" (accent on the nyah part). For uno, I guess I'd just say it sounds like "boo-no" without the b. Tres is close enough (the T and the D are different, but it still rhymes to my ear).