new training program advice

Well I am back at it again this week after 1.5 weeks off due to sickness and I have a few questions about a new program I was considering:

Here are the distances I can currently do. I started the first of the year and am gunning for a sprint tri this summer or fall.

Swim: 600yds continuous free, more if I do a few laps breast and then continue but 600 is the most I have done so far consecutively.

Run: 2miles at ten minute per mile pace. This is the hardest for me. Probably becasue I am 30 lbs or so over my "ideal"weight of 180 and still getting over my smoking habit of ten years.

Bike: Before I started training I would bike 15 miles without much trouble but since I started I have not done more than 5.

I was using Michael's program but I thought I was going too slowly so I would like something a bit more burly. However, I am also afraid that my sickness was partly due to being rundwon from doing brick workouts and following them with weights.

Here is what I was thinking for my new program.
M: Run 2 miles@ 10min per. Walk 5 minutes between miles to get my heartrate down (it was going up after i crossed the 1 mile mark yesterday.
T: Bike 5 miles
W: Swim 400 yds
R: Run 2 miles as above
F: Bike as above
S:Swim as above
Sunday off

Then I was going to bump up slowly. Is this a bad idea? I am a bit concerned about the couch to sprint program on here as it would hagve me doing the full sprint tri distances in the second week! That seems too much to me.

What should I be doing here? Do I need to do light and heavy days? What kind of increments should I bump in? How far do I need to be able to go in each distance to do them all back to back ina sprint tri? (keep in mind my goal is smply to finish.

Any advice is greatly appreciated.