Marlin came out with the latest upgrade, which is called the XT-22, announced at the 2011 ShotShow...
so the 981, 881, 781 and all previous models are now...previous
Several Models are available now...hit up
http://www.marlinfirearms.com/Firearms/xt/XT22.asp
Profire Adjustable trigger...other neat mods...
OK, for a stock...they're not doing wood on the tube-feds...yet.
So your best bet is to grab a Boyd's 900-series stock and slap it on.
The well for the new trigger may need some slight expansion, but that's it.
The Boyd's stocks come in several types, at different times of year, so check their website for more info...
If you don't see a stock pre-made for the 900-series that you like that they make already, put in a request with them...
when they do a run, they'll give you a three-day advance warning so you can prepare to order it up
http://www.boydsgunstocks.com/Replacement-Stocks-for-Marlin-Rifles-s/124.htm