Grymm - we're on the same page. Each modeler needs to set his/her priorities. I just don't want to see anybody go into an enormous project like that without knowing what he/she is getting into.
The Heller Victory and La Reale are indeed better kits. (This Forum contains several threads dealing with the former.) I especially like La Reale. I'm no expert on French galleys, but it certainly matches the drawings and artwork I've seen - and the "carved" decorations are just as well-executed (and almost as numerous) as those of the Soleil Royal.
Unfortunately La Reale seems to be out of production; if you find one my suggestion is to grab it. The "new" Airfix 1/100 Victory is a repackaging of the Heller one. One point to consider: folks who've bought the Victory recently report that the plastic is brittle and prone to serious warping. That wasn't always the case. If I were in the market for a Heller Victory I'd try to find an older one - either in an old, well-stocked hobby shop, on the Web, or at a flea market or auction.
Regarding the kit blocks and deadeyes vs. aftermarket replacements - there's no need to make any decisions about that at the moment. But be warned: the only way to make the kit parts work would be to file a groove around every one of them. And there are several hundred.
As for ratlines - we've discussed that subject in the Forum several times too. My own opinion, based on 50 years of ship modeling, is that the Great Ratline Problem is a hoax perpetrated on innocent consumers by ship model kit manufacturers. Rigging ratlines to scale actually isn't hard. It takes a fair amount of time, but nowhere near as much as many people seem to think - and probably not much longer than using any of those jigs and other gadgets would take. If you haven't started the kit yet, you're months away from having to worry about ratlines. When you get to that point, you may want to look over this Forum and see how other folks have dealt with the problem. It really doesn't need to be intimidating. If you can put all those guns together, you have the necessary dexterity to rig ratlines.
Regarding gold leaf - I tried it on my Soleil Royal, and didn't like it. (Admittedly I built the kit about 25 years ago, and some new products have come on the market since then.) I found there were a couple of major problems. First, in order to work properly the gold leaf itself has to be laid on a smooth coat of sizing, plus the adhesive varnish - and each additional coat of anything, of course, tends to obscure the detail of those beautiful castings. Second, though gold leaf is extremely thin (about a millionth of an inch, as I understand it), I found that the tiny compound curves on those Heller parts were too much for it. The finished product had a slightly powdery appearance - not the shiny, shimmering, metallic look I had in mind. When I compared a trial run with gold leaf to a similar sample of Humbrol gold enamel, the Humbrol won out: it actually looked considerably brighter, smoother, and more metallic.
The nicest-looking gold hobby paint I've ever encountered was made by a now-defunct British company called Rose Miniatures. It came in two parts: a small vial of metallic powder and a bottle of amber-colored varnish. The modeler mixed the two together, and the results were great. Unfortunately I haven't been able to find anything of that nature for many years. I've found "gold powder" and varnish in art supply stores, but it's all been considerably coarser than the old Rose product. The gold paints made by firms like Humbrol and Testor's, though, are actually mighty good. Maybe you'll have better luck with gold leaf than I did, but I do suggest doing some samples with various other products and comparing the results before you commit yourself.
If you have a twelve-year-old who's interested in ship modeling, you're an extremely lucky man. My efforts to get my stepkids interested in model building - or any other constructive leisure-time activity - were among my more dismal failures. However that model comes out (and I suspect it will be spectacular), every hour you and your son spend on it will be an hour well spent - and an hour I'll envy. Good luck.