Thank you for your inquiry. I will send you detailed information about the China cruisetour possibilities for June, 2006. There are cruisetours centered around Yangtze sailings of 3, 4, 7, and 9 days. I recommend the itineraries that include the 7- or 9-day sailings, although others prefer shorter cruises and longer land travel.
You inquired about including Guilin, Suzhou, and Xian in your itinerary. Several of Viking's cruisetours include Suzhou and Xian--in fact you stay overnight in Xian. However, Guilin is not included in any of the itineraries--except as an add-on package. Viking offers a 4-day add on, either pre- or post-cruise (depending on the direction you are travelling), which includes 3 nights in Hong Kong and 1 night in Guilin. I'll include pricing and date information for that add-on.
p.s. China can be very warm in June and July. Is it possible for you to travel in early May or in the fall instead?