Good idea for you to mount the sending unit on the chassis to reduce it from vibrating.....live with what you happen to have. Mount it so it's easy to get to, for servicing if you need to.

I use manual gauges that require no sending unit and nothing electrical.
The gauges come on when the engine fires up. Less parts mean less to fail.

I avoid hard lines for oil lines, since I think hard lines will vibrate and fail sooner than a flexible line. I for sure, would avoid hard lines in a turbo application...too much at stake.-Bob