I am interested in classical groups (in particular $SL_n$, $Sp_{2n}$, $SO_n^{+}$) over finite
rings of the form $R_k=\mathbb{F}_q[t]/(t^k)$ for some prime power $q$ (where $q$ is odd in the 
orthogonal case) and $k \in \mathbb{N}$. Over a finite field, the maximal subgroups of the 
classical groups are known, and so it is for example known that any two semisimple elements of 
orders $q^n+1$ and $q^n-1$ generate the group $Sp_{2n}(\mathbb{F}_q)$ (and similar results for 
the other classical groups). I am wondering whether 
it is true that any two semisimple elements of orders $q^{n(k-1)}(q^n+1)$ and $q^{n(k-1)}(q^n-1)$ generate 
$Sp_{2n}(R_k)$. Is anyting like this known? Are there lists of maximal subgroups for classical
groups over finite rings? I would also be interested in similar results over $\mathbb{Z}_p/(p^k)$.