There isn't much chance of finding a decent TE in the free agent pool, unless someone drops one for a bye week. Stick with what you have but keep your eyes open.
WR, on the other hand, may still have some talent in your free agent pool. Various pools this week still have: Donald Driver, Deion Branch, Brian Finneran, Qadry Ismail, Joey Galloway, Antonio Freeman, Ike Hilliard, Quincy Morgan, Troy Brown, Josh Reed, Muhammad Muhsin, etc. Some of these guys have injuries, some aren't starters, and others just seem to be there because the good players have better and the bad players can't recognize talent.
If you trade away a RB for a WR, you are going to take a hit at depth where it is most difficult to fill. Every free agent pool has WRs worth starting; very few have reserve RBs.