What size of tyre on a 20 x 9.5 rim ?

[CO72]

Hi all, 1st post from sunny Scotland

Ok I am going for 20" Star 5 Alessio's (http://www.alessiowheels.com/)

They only come in a 9.5 " width
I have been told that a 275 40 20 is the widest tyre that can be fitted to a 9.5 rim by Toyo but some wheel dealers have said a 295 would be ok but it would either be as I see it (in the case of a 45) too large an overall dia or (in the 40) be too wide as a 10" rim is needed (as per Toyo's spec sheet)
Is 275 40 20's a good choice ? (I don't want the rubberband look)
Thanks again for any help & if anybodys got pics of a X5 with this tyre all round please post.

Cheers

Co.