Do look into the DL50. I just ordered my second one this afternoon...$390 with a muffler. Their web site is http://www.dlusa.net/

This is the big thread on the engine. Initially they had faulty Walbro carbs, and support issues. DL replaced the all the carbs in the field and set up a local distributor who is providing excellent support.
http://www.rcuniverse.com/forum/m_5532868/tm.htm