I am having some serious trouble with my glasses and the sights on a VZ-2000.  Nothing wrong with the rifle and I like it a lot, but could sure use a low-power scope or red dot on this thing.

Am I correct in thinking that a sort of scout rifle arrangement with a sight placed on the rail of a replacement top hand guard is about the only practical option?  I remember there was some talk of a small stretch of rail held on the bolt cover with magnets, but that didn't sound like a really good idea.

Am I missing anything?  Or should I just face the music and start saving for one of those fancy railed handguards?

You can actually buy and install a side mount rail on your VZ from czechpointusa. You'll likely need to have a gunsmith perform the install if youve never done one. The other options are as U started, the sketchy magnet, or the top handguard rail. If going the top handguard rail method. I would be weary of the mako/fab poly guards. The fab aluminum rail at $230 is good but pricey and no cowitness. NEA (~$110) makes a light rail that allows co-witness as does bonesteelarms (~$100 or 170 with lower). I use the later and would suggest both over the fab since I prefered lighter options with co witness. Let me know if u have any questions. Here's my VZ with the bonesteelarms upper and lower guards.
http://s12.postimg.org/ai7ukz3st/image.jpg

Or if you're cheap like me you can just drill a few holes and mount a carbine length picatinney rail to the top of the stock handguard. Hardest part was rounding out the back of the aluminum rail to fit the curve of the handguard. I used a spare Midwest Industries rail I had lying around, buying one new is under 10 bucks. I also picked up a used top handguard off ebay for $7 and stored my original handguard, so if I wanted to go back I still had the original matching handguard. Unlike AKs, the top handguard isn't just beaverbarf. There's metal underneath which makes a secure mount if you drill your holes with as little slop as possible. I'd also recommend taking a file or dremel and filing your protruding bolts down flush with the mounting nuts just so you have maximum clearance with the piston. Only downside is this setup won't give you cowitness but with a TRS-25 red dot it's high enough to get a good chin weld.

There are a couple optic mounts out there that mount to the rear sight base. Obviously  no cowitness though.

This is by far the best option:

bit pricey though..
(Zendl/ gunexpert.cz)

I just use a side mount and ACOG. Repeatable zero +/-1MOA so you can pull it off if you want to use the irons

http://i1023.photobucket.com/albums/af352/Breastman/Gun%20stuff/07C0BBA7-DBC6-42D9-B7BC-16C38ADE8C6D_zpst05r4sgo.jpg

I just noticed this post.  Can you tell me more about these mounts as they sound ideal for my purposes.

Here ya go:
http://www.primaryarms.com/Scout_Scopes_VZ58_CZ58_Scope_Mount_Black_Anodi_p/ss-04095.htm

It just basically replaces the rear sight. However, this means no irons in case your RDS fails.

I also found this mount, but know nothing about it:

ScoutScopes