Please, use the standard conventions for each language (or somewhat very close to the standard).
- More consistency in each piece of software itself (because it will have the conventions that really apply)
- More ease for additional (external) fellow developers. They must not learn "inconsistent" styles.
- Easier comparison/review/transfer of code out of / into examples in the "world outside"
- No regrets later, see below
Here's what I experienced:
I am currently working in a shop where they first did Java-only projects. Then, they started to do C#/.NET and applied the already-well-known Java styles/Naming conventions to those C#/.NET projects.
When I (and others) joined the team, after doing C# for years, I was really annoyed with how the code looked like and had a hard time to continue with the perceivedly awkward Java-style in the C#/.NET projects.
Later they figured, that having a "wrong" style is bad, and started to adopt the C#/.NET conventions in new C#/.NET projects. Now we have really mixed up styles - sometimes different within a platform, sometimes different in the projects. Hopefully, over time, we will write less Java-styled C# code, but in my perspective, it would have been better to never start out doing that at all.
What you could do
- Consistent brace rules (Opening one on new line / same line)
- Consistent commenting rules (e.g. XML only)
- Rules about code quality (length of methods, unit testing frequency etc..
- Use a tool to help applying the above
What you really should keep per language / platform
- Casing of identifiers
- Naming styles for identifiers