You should have no trouble carrying a load for your trip with the current setup. I would encourage you to take a short weekend trip ahead of time to test out your gear and loading. I attempted my first loaded trip in May and had to call it off after realizing that my bike didn't handle safely with all the weight in the rear. Picked up a front rack and panniers to better distribute the weight, and all went well on my first successful loaded trip a couple of weeks later.

After considering various lightweight tents, I ended up buying a Quarter Dome 2 from REI Outlet for a good sale price. Altho it's listed as a 2-man tent, the size is about right for one person with gear inside the tent. It only weighs 4 lbs for the tent, fly, poles, stakes and ground pad -- and easily fits inside the panniers (including poles).