I can't really tell or found any specs on the Paradigm Monitor 7 V4s, but it looks like the V4s were the last to use 6.5" mid and bass drivers. It seems they shrunk their monitor line from V5 on to favor the trend towards smaller sized speakers these days. I had a pair on Monitor 7 V1s from 1997 and loved them, but decided after 12 years that it was time to upgrade. I looked at the Monitor 7 V6s (the current versions) and found out they have been shrunk. From V5 on up, the Monitor 7s now use 5.25" drivers. I ended up going for a pair of Monitor 9 V6s to stay with 6.5" mid and bass drivers and matched them up with a CC-290 V6. I got my CC-290 V6 first and decided to hook it up with my old Monitor 7s just for the heck of it. From my experience, you won't have too much trouble matching any series Monitors up. They've pretty much stuck with titanium tweeters through the years and really, that's all you need to match up the most (in my opinion). The CC-290 V6 matched up fine with my old Monitor 7 V1s and even made the front soundstage better due to the CC-290's 3-way design.
I'd say you can't go wrong with the Monitor 7 V4s, but I will also say to match them up with a good dedicated Monitor center channel. Paradigm's newer 3-way center channels really improve teh spaciousness of the front sound stage and so it would be great if you can get a deal on CC-290 V5/V6 or the beast of a center CC-390 V5/V6.