Anyway, I want to try a new foundation under the mattress before running out and buying a whole new mattress system. The mattress is mostly coils, with only the thin layer of latex on top. I was reading that a latex bed should be on a wood foundation, and that an interspring mattress should be on a coil foundation.

Anyone have any guesses which would be best for my setup? It is a European Sleepworks bed if anyone is interested, sleepworks dot com.

Thanks.
Barbara

Here's my personal experience with mattresses.

I had a spring mattress and now have a latex mattress.

One spring mattress was in a CalKing platform (no foundation), it was Ok.
Then, we bought another spring mattress (RestWell) on a box spring foundation. We had problems with the mattress after 7 years, and the company picked it up and returned it without charge.
We had to have a bed while this was being fixed, so we bought an Essentia pure latex mattress, which can be either placed on a box spring foundation or a platform.

My wife and I both prefer this pure latex mattress, and haven't even opened up the repaired mattress mentioned above. I should say that we are using the box springs used for the repaired mattress (we have sinced ordered higher box springs, to replace the 4' box springs that we purchased with the repaired mattress).
After saying all of that, I think your problem may be with the foundation you are reluctent to get rid of, and to further confuse you with which mattress with what foundation.
If you can, I would recommend the mattress that we bought from Essentia (made in Canada).

Good luck!

Thanks.
Barbara