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You don't really need Win 3.11 for that — unless you're simply curious. Windows 98SE will do just fine and is more appropriate for this machine. It has a real DOS mode that is just as good as a "pure" MS-DOS 6.22. Also, it has a lot more software available, including Daemon Tools for mounting CDs, latest versions of Total Commander for network transfers and other useful stuff.
Sound Blaster Live! may not be the most compatible option — depending on what kind of games you want to run. Generally, for DOS games you might want to find an ISA soundcard, like a Soundblaster 16/AWE32/AWE64 or many, many others. You'll really have to do some research on that, as there is no single "best" soundcard that everyone likes. But first, check if your motherboard actually has ISA slots. Pentium II motherboards usually had them, but since you have a Compaq machine, there can be some surprises. Also check if it has any integrated audio and video — it might give you some options.
Riva is also a bit too "modern", but should work OK. You can pair it with a Voodoo 2 for some Glide games, if you want. Also, if you can get your hands on a cheap Diamond Monster Sound MX300, do that — it could be nice if you ever want to play some late 90s Windows games on that machine.