Can you start a sentence with Or?

Yes, but it's not recommended.

Explanation:

Based on the experiences i have had with teachers, they don't seem to like the idea, as it doesn't sound very professional and academic. Try using synonyms like:

as a choice.

as a substitute.

as an alternative.

conversely.

either.

in other words.

in preference to.

in turn.

no its not a run on sentence however i think you meant wet suits not sours also a run on sentence would be like surfers surf all winter long in southern california by using wet sours to keep them warm and the live their all year long  

what are the phrases to choose from?