I've never been to Vara so I can't comment on that.
For Havana I like the Habana Libre's humidor (the tall one close to the Hotel Nacional), you'll rarely want for quantity. Selection last week was predominantly regular production, but for all marcas. Although you are going right after the Partagas festival so stock may be a little lighter than normal. Side story, when we landed in Havana on the 9th the first spot we hit was the Libre, as soon as we walked in there was a group that was making a big purchase, maybe about 2/3 mastercases worth stacked on the counter and in boxes on the floor. We walked into the humidor and there was still ample supply, all shelves were full. We went back the next day and it was starting to empty with three/four shelves cleared out. Regular stock included two 50 cabs of Punch DCs. I can't remember but they may have also had a few 50 cabs of RASS, about 17 boxes of Sir Winnies (yes, I counted). THey also have copies of the MRN book, in Spanish though.
I've never had an issue walking into a humidor in Havana except the Nacional. At the Nacional sometimes they get a little standoffish if you want to go in but the door is locked. Since you plan to hit that up take the ten minutes to walk to Habana Libre.
As stated above the Comodoro/Melia combination would work. Although I've never been a big fan of the Comodoro (small as f*** and not much to choose from), Melia is good for its lounge.
Your other option (although I'm sure others will sh*t on me for it) is the Vara airport humidor. They won't let you in though, but you do have a good view of their stock. They usually have good stuff, not as varied as the Habana Libre but good stock nonetheless. I've picked up some good boxes there, 2012 Sir Winnies (in 2014), RE/LEs. When we flew out of there on the 13th there were about 8-10 boxes of SLR Cuba REs. Only one word of warning, if you're buying by credit card at the airport they hose you anywhere between 10-20% over the list price. But then again, living in Canada that's still plenty cheap for me.