Disclaimer: no guarantee for anything I write below to be working for you!
I have
M-Tec 68030 accelerator from A500 (not for sale) and it works in A1000 (it even works together with ancient CPU slot memory expansion -
Spirit Inboard, so all together I have 6MB with A1000 mem + A1050 + Inboard + M-tec). The only problem is that in order to fit it, I had to remove FDD as it comes in the way of accelerator (now it hangs on cables outside the case), plus case does not close anyhow, as this old Inboard 1.5 memory is huuuge and raises CPU socket too high. I am trying to fix both problems: I am trying to build CPU riser designed with help of one colleague, to relocate CPU socket so that M-Tec fits together with FDD. As for Inboard - it is huge, and not much I can do about it, so I'll either skip it in favor of IDE (without memory), or, I'm searching to buy another CPU socket memory expansion, hopefully more modern and not that huge.
I have not tested it yet with CPU IDE controllers - I've ordered one (just IDE68K based, no memory), but still waiting for it. I can post here when I have a chance to test it. Some forums say there can be a conflict and that M-Tec accelerators would not work with IDE68K derivatives.
So, no guarantee that it is going to work with every A500 CPU socket accelerator... and no guarantee if it is going to work together with IDE68K boards... but if you are feeling brave, you can try to find one A500 accelerator, and see if it works

.
Good luck, and have fun!