Will these wheels fit an 8 ?

I've been down that route: There are many wheels on sale from E39s. They will fit BUT:

1.) You will need hub-centric rings to reduce the larger centre spiggot diameter of the E39 (approx 74mm) to the smaller diameter (approx 72mm) of the E31 and most other BMW. Rings can be bought for about £25 for a good set of 4 machined, aluminium rings)

2.) The offsets will tend to be greater (typically ET46) for many of the E39 wheels, whereas around ET20 is ideal for the E31. To correct this you will need spacer rings (H+R cost about £200) and longer bolts. (A lot of hassle). Check the actual offset on the set that you are being offered. If it is between ET18 and ET25, you should be OK.

2.) The sizes you mention in your listing are not ideal. Better to have larger width rims (eg 10J) at the rear and smaller (8.5J ) at the front. From your picture, there also appears to be little tread left on these F1 tyres.

In my oppinion, unless, you can get them very cheaply, you're better off waiting for the right set to appear. There are usually quite a few E38 wheels on sale in various places and these tend to be a perfect fit, particularly if you find the 18" M-parallels (staggered widths) that were standard-fit to many E38-sport and were original equipment options on the later E31. Otherwise, 17" genuine Aplinas come up every now and then, too.

If you come across a set of Alpina 18" 'soft-lines', in staggered widths, as commonly fitted to some E39, then it's probably worth the hassle of spacers and spiggot rings.