It you've been Trad climbing for 20 years, I doubt you'll be happy getting herded into some standard course for 6 days.
Rather hire a private guide (who might offer you a similar rate if you guarantee 6 days).
Wouldn't be surprising if a good experienced guide had _you_ doing the leading by the second or third day (at least for non-crux pitches).
. . . (I know some who are oriented that way, but I want them to be free for _me_ next June).
also . . . Chamonix is not a great place for solo acclimatization climbs.
Might want to learn about non-expensive chemical tricks.
Ken
Post edited at 19:41