Engine options

[Mbgasplumbing]

Have been looking into potential engine swap for my caddy now for a while ,it’s currently 1.9 tdi code bls and as we speak has no issues.
I really would like a completely refurbished engine that is like new again but….something which is a little more powerful and able to tune what are the sought after engines ideally as a straight swap may be favoured, it’s my daily work van so can’t have it off the road for long thanks all.