Hey cannon. Welcome!
To me it sounds like you’ve done some good base training and have some good fitness, but I still think going into build would be tough.
Having said that, what I might recommend is jump into SSB II for six weeks and then see how you’re going. From there you could drop in 4 weeks of a build (General Build, maybe) or possibly drop in 4 weeks from the sportive or rolling road race specialty.
SSB II has some good VO2 work to help your top end, but still gives you plenty of muscular endurance work to build out your aerobic systems.
Finally, it’s awesome you have the time to commit to MV, but maybe start with low volume and supplement for the first few weeks. If all still good and you’re nailing every workout, move to MV.