Longer butt plate for FX Impact

Before I go make a deeper butt plate for my FX Impact, I was wondering if anyone knew of any any commercially available replacements? The stock butt plate is just a little short for me and I'm looking to make the stock a little longer (via increasing the depth of the butt plate) so I can shoulder the rifle nicely. I've seen a monopod butt plate replacement which looks like it would add a little depth/length (and a monopod!) but I'm not sure it's going to be enough.