Your Pentium MMX machine is quite OK as many others suggested. For the graphics adapter, considering you will use it only for non 3D games (Windows 3.11 and you already have a Voodoo in the system), I would suggest a Matrox Millenium II (8MB RAM, upgradable to 12MB, so, supports high resolution true color modes, excellent Windows 3.x support, very high quality 2D output). Probably your Savage is also ok, but I have not much personal experience with that card.
10Mbit is not your only in option in theory, since there are 100Mbit 3Coms (905 series) all around and they have excellent WFW 3.11 support. Realteks and Intels are also suggested by many, but unfortunately I have no personal experience with them (my only Realtek is 10Mbit and I have no Intels). I don't know any gigabit cards with WFW 3.11 drivers, though.
2GB is the maximum partition size that Windows 3.x "supports" under normal conditions. Actually this limit comes from MS-DOS 6.22, Windows works with any partition, the DOS version it works on will support. It's possible to install WFW 3.11 on top of a newer DOS version to support FAT 32, hence larger partitions (like MS-DOS 7.1 that came with Windows 98) but this requires some tweaks and actually I don't think it adds much value. SATA drives? I again, against the idea. If you really need to use them, then I suggest utilizing SATA to IDE adapters, not SATA controller cards.
GA-6VTXE PIII 1.4+512MB
Geforce4 Ti 4200 64MB
Diamond Monster 3D 12MB SLI
SB AWE64 PNP+32MB
120GB IDE Samsung/80GB IDE Seagate/146GB SCSI Compaq/73GB SCSI IBM
MSDOS 6.22+Win 3.11/95 OSR2.1/98SE/ME/2000