The open blocks tank is a reasonable substitute for for the BC thermometers, as are the TE portable tanks. For real volume in a temporary set-up, a stack of drums (also open blocks? extraUtilities) are nice. The lite packs always seem to have the big mods I don't want while leaving out my must-haves.
I actually have added SGCraft (adds stargates), ArchimedesShips (adds large platform flying & sailing capability), EnchantingPlus (easy to choose your enchants), Sync (clone body swapping anywhere except the end), and Big Reactors (larger scale RF production).
What I'm looking for in additional mods are narrow focus, cool or especially useful features, minimal world gen with a clear use for everything, a relatively simple & straightforward tech tree. I'm looking at atomic science (particle colliders! Antimater!, & MFFS belongs in a pack with Stargates and might require more power if I ever get around to using it).