I don't know about the V4B, but I know the V4-BH is essentially a (not so) mini SVT.
I would definitely pick the V4-BH over the SVT-4 PRO. The V4-BH just has a much fuller sound - most likely due to the tubes. The SVT-4 PRO always sounds kind of sterile to me.
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What he said! 100 watt tube head can be a great stage monitor with AWESOME tone. The 4 PRO is clean and warm, while the amp you are looking at will have some great overdrive from the power amp section.
I'd take the V4BH all day, it's a re-issue of the V4B. But I'd pick it for it's fabulous warm tone. If you need major volume, the 4Pro has tons more output power.