Danny, doing a search will find you loads of threads about this.
Regardles of type, the CAA limit is everyone must own at least 5%, so you could never have more than 20 in a group. Plus you'd probably never have any availability!
However, I have 1/10th share in a C-172, it's £60 / month & £65 an hour wet. It's on the expensive side, but it's in great condition and meticulously maintained.
DW