Suspension forks and shocks have progressed so much in the last few years it can be hard to keep up with it all. Forks have become lighter and travel has increased with no loss in efficiency either. Road forks are becoming lighter and more aero as well as increasing in diameter so make sure you check your headtube width.
All forks are relatively easy to replace as long as you have the same size steerer width. Remember to check that suspension travel length on mountain bike forks will not affect geometry or handling. If you need to replace a rear suspension shock on your mountain bike or simply want to upgrade there are plenty of options.