Mixing engine mounts?

[Matra]

It seems that I have to replace the two lower engine mounts on our S40 (2001, 1.8 petrol, automatic transmission).
I tried to find a spare for the front position (P/N:30819188), but it seems that it is discontinued and hard to find, or really expensive compared to the rear one.

The question is, what happens if I use another P/N, which is for another type of petrol engines? E.g. 30611143, which is for more powerful engines (all gasoline engine with turbocharger, automatic transmission).

I suppose, these mounts are mainly to prevent engine tilting during acceleration, so it should not cause any problem or excessive vibration. Maybe I am wrong...

I saw full sets of engine mounts on ebay, all four for reasonable price, but only for the turbocharged petrol engines with auto trans. What if I try those? 3 of the 4 P/N would be the same, but not the front one...

If we are talking about engine mounts, has anyone replaced the right engine mount (the black pot lookalike P/N:30611474) with the old type mount (P/N:30630070)?

Thanks for any comments and advice in advance.