nice recipe! I've made something similar before - quite tasty.
Well, there are three things you could do -
1) Increase your mash temp to 154-155
2) Add some Carafoam to the grist - maybe 2-3%.
3). Increase your current crystal malts.
If all you want to alter is the body perception, I would start with #1 and see what the result is. If that doesn't work, try #2 or #3, with the former being opted if you are happy with the level of caramel flavor currently, or the latter if a little more caramel malt flavor would be okay.