I am afraid you will have a bit of a trouble finding italian speaking guides - but then again, I can't really see why would you need a guide to begin with.
In 15 days you have several options, mostly depending on your budget and on what you like to do. Two top attractions in Uganda - visiting mountain gorillas in Bwindi and trekking in Ruwenzori are both very expensive. And if you choose to go to Ruwenzori it would probably take most of your 15 days leaving very little for anything else. Trekking gorillas, however, is not to be missed - it is a magnificent experience and worth every penny you pay for it. The south-western part of the country by Rwanda border is very beautiful - try the road from Kabale to Lake Bunyoni, but do take bodaboda and not the bus. Lake Bunyoni is a nice place to chill for a few days, although the constant flow of overland trucks is somewhat annoying there.
If you want to go to safari, Murchinson Falls is a nice place, I hear. Jinja is only two hours from Kampala and is one of the best spots in Africa to do some whitewater rafting.
In the east, Sipi Falls, a few hours on from Mbale is a beautiful walking country and if you're up for it you can climb Mt. Elgon.
For a lazy few days on the beach, Ssese islands is a good spot - take some books as there is nothing to do apart from lazing in the sun and reading. Well, you can also rent a kayak from Hornbill Campsite - that will keep you busy for a few hours. There are local boats travelling between Ssese islands and Entebbe so you don't need to backtrack through Masaka when heading to Kampala.
If you have any specific questions you can send me a message and I will try to help.
African Connection has a great guide in Uganda. The website is: www.ac-safaris.com/uganda.php
Don't know about translators, though. Sorry.
Red Chilli's Hideaway is a great hostel to stay in while in Kampala. www.redchillihideaway.com
You must see the Kibale Forest National Park where you can go on chimp treks and stay in the sweetest little bandas or a large tree house in the forest. From the tree house one night we got to see forest elephants tromp through the grass. SO amazing! There are other animals, too... baboon and tons of monkeys! Also the most diverse butterfly population.
If you are interested in village life I can recommend some places off the beaten path.
I would also recommend Queen Elizabeth National Park. The accommodations are great and the food (so good!) is included in your stay if you pay for the posh rooms. There is also an option for less extravagant bandas. I have done both and found either to be enjoyable. Though I did not see any lions, I heard them roaring at night and even saw paw prints in the dirt. Friends who were camping just a ways away from the bandas had lions sleep next to their tents! The boat ride of the Kazinga Chanel is great. You see tons of wildlife from the boat: hippos, elephants, birds, buffalo... We went on both walking game tour and a game drive. I rather liked walking, though we did see a leopard on the game drive and not much on the walk.
Let me know if you have any other questions that I may be able to help with.