1.  Since you're investing the proceeds of the 1031 in multiple DSTs, I'd split the carryover basis by % of investment.....

2.  Find out specifically what year end documentation you'll be receiving from the trustee(s). Get a sample if you can. 

3. Id file a separate Sch E for each DST using their year end statements, splitting and depreciating the carryover basis among the DST's 

DST 1031 exchange investors do not receive a K-1 or 1099 at the end of the year for tax purposes. At the end of the year you will receive an operating statement (sometimes referred to as a substitute 1099). This will show your pro-rata portion of the DST properties rental income and expenses.