I have 2 goals I'm shooting for this summer and am not sure if they compliment each other or if I should toss one.

My first century this summer was 3 weeks ago and I really wasn't able to train much at all because of work and weather and illness. I wasn't able to hang with my friends that were in shape so I rode mostly solo and jumped a few pace lines in the latter part of the day. It was head winds all day and had some climbing only about 4000 ft and topped out at 7600 ft. My time was 6 hrs 40 mins of peddal time with 3 short stops for water and a toilet. I finished really strong and should have started pushing for the finish sooner as I had too much still left at the finish that I could have spent if I hadn't messed up my split times.
I have never ridden over 130 miles in one streatch. I want to break a 5 hr century this summer and also do my first double. I won't care what time is on the double. The goal is to finish. I'm thinking that both goals should come into the picture about the same time and that the training would be about the same for either goal. I currently ride two 50's on the weekend and 2 or 3 30 miles weekday climbs 20-30 miles with 4000 ft gain.
I am pretty sure I could easily push my weekend rides a little further and/or do them faster, 3 hrs currently. I'm way too much over weight to do any better on my hill climbs until I shed some fat (250 lbs)

I think I could probably do the double easier than the 5 hr century.

DO you guys who have some experience think I can shoot for both of these goals at the same time? If not,,,, what one would be best to improve my over all fitness?

Yea ,, I know the weight thing is a big part in this. That's why I started riding a couple years ago but I'm really loosing the weight battle. I have just become a fat old man that can surprise people when I get on a bike. Most of that is probably heart, stubborness, pride ect. I get more from my heart/tenacity than I do from my fitness level.

Thanks for any comments