Sprint to Oly training

I've been training for 3 months and just completed my first sprint this weekend. I finished upper MOP for my AG (M3539). I would like to do an Olympic length in 8 weeks. My run volumes are high as I did a 1/2 mary in June and am training to do a full marathon with my wife in October.

My sprint training was essentially: Swim, 3 times per week for 800-1200m concentrating on technique since I could barely do 100m continuous 12 weeks ago. Bike, too low of mileage since I did not resurrect my old road bike until early May and my run volume has been so high. I counted on the fact that since my teen years I could hop on a road bike and rip out 25 miles at will. Run, 25-35 miles per week, one speed/hill workout, one long run per week. Total hours are loosely based on a volume schedule.

My training logs are up to date so you can check them out, but my general philosophy is outlined above.

I'm considering doing a similar volume based plan for the next 8 weeks adding in swim mileage and biking mileage. I also have considered a more rigorous plan such as the Silver Level Sprint to Tri 12 week program starting at week 4. Having a more specific training plan will help my performance, but I'm afraid that I won't like training as much if I have to track specific workouts, intervals, routes on a daily basis. The specific workouts in the Sprint->Oly plan seem like both a blessing and a curse.

I'm not looking to be competitive, although I do not want to embarrass myself. I have a personal goal of doing a full IM someday and HIMs look like a nice sweet spot for where I'd like to be competing in general. For this year I want to get my first tri out of the way (sprint, check!) and hopefully move up to an Oly to get a feel for it. I can already do the mileage for each of the events individually with the exception of swim (although after this weekend I suspect I could swim a full mile of need be).

I'm not opposed to spending money for the silver plans or a good plan in general, I just want to have something productive and fun to train. As always any advice you veterans can give is greatly appreciated.