Should I send Collectcorp a letter explaining my financial situation?

First post and just starting the process... I'm unable to pay my debts due to numerous negative developments over the past 5 years - telecom employer went bankrupt, unemployment for a year, divorce, and more. I've stopped making payment to creditors in an attempt to get close to break even and stop overextending beyond my net pay while I try to negotiate settlements. If I can't settle with all or most I might still ahve to file Ch. 7.
I have 3 accounts with AMEX - Green Charge, Blue Credit, AMEX Starwood Credit. Yesterday I was contacted by Collectcorp about the Green and Blue and today I got a call from United Recovery Systems about the AMEX Starwood card. Is it typical that two CAs have been contacted by the same creditor? Thoughts on either of them (been reading the threads but any fresh feedback is welcome)
Collectcorp was very polite to my surprise asked me to write a letter explaining my situation in greater detail providing as much proof as possible since a lot of my outlay isn't only credit debt, but other loans and child support and none of that is evident in a credit report and shows why there is no more money to give. I can prove all that without divulging account numbers and paystubs. Does anyone see anything wrong with providing that letter? It actually makes sense for them to see the big picture. Has anyone done this and found it helpful? Thanks.