I second Jameswei ....you should stick with the same manufacturer - your best match is actually the Studio 110...as it has matching drive units!
1SC's would probably be the next best choice but poor in comparison due to their reduced dynamics relative to your big 140's. It is impossible to achieve balance and a decent HT sound if you mismatch mains and surround speakers too much. (You end up with a system that only sounds right at some volume levels and not others...and if you use completely different speakers form different manufacturers then all I can say is, well, you have a dogs breakfast of an HT system and it will sound that way too)
1SC's would probably be the next best choice but poor in comparison due to their reduced dynamics relative to your big 140's. It is impossible to achieve balance and a decent HT sound if you mismatch mains and surround speakers too much. (You end up with a system that only sounds right at some volume levels and not others...and if you use completely different speakers form different manufacturers then all I can say is, well, you have a dogs breakfast of an HT system and it will sound that way too)