Well, you could make it really easy by buying the buck riveting kit available from Vintage Trailer Supply. Might not be the BEST on the market, but you aren't building an airplane from scratch, you are doing repair work. As far as rivets goes, you can get these from VTS as well. Use the 5/32" Brazier head solid rivets for pretty much anywhere that you are replacing a bucked rivet. The only exceptions I can think of is in some of the window frames, there are smaller bucked rivets, but you may not need to take these apart.
http://www.vintagetrailersupply.com/...-p/vts-843.htm
You will also need a pneumatic pop-rivet gun. Most of the pop rivets in the trailer are either 1/8" or 3/16". A $30 gun from Harbor Freight will do the job just fine. You will never need a 1/4" mandrel pop rivet, so don't bother with the more expensive gun. Use only aluminum mandrel pop rivets. You can get these at the local hardware store, or from VTS and various online suppliers.
good luck!