More speaker or more power

More speaker or not is a question of your room size and acoustics. Generally higher efficiency is a good/better thing in order to get high SPLs easily with moderate power.

However, if you like your speakers, I would instead recommend you consider the Sanders ESL stereo block. It is a terrific amp which can go loud with great control and lots of reserve. IMO this amp is greatly under-rated.

go klipsch go

If you want a large increase in headroom, more efficient speakers is probably the way to go.

Let's say you'd like 6 dB more headroom. You can get that from a fourfold increase in amplifier power, or by going from 86 dB speakers to 92 dB speakers. Not only is the latter probably more cost-effective, but I strongly suspect the VR-4's would exhibit serious thermal compression at peak input power up near 500 watts. So you'll also get better dynamic contrast with the higher efficiency speakers.

Duke
dealer/manufacturer

I'm with Jaybo and Duke....speakers. If you go pro speakers they won't sound so dull or lifeless at higher volumes. (thermal compression and as the cones exceed Xmax)

(BTW: Due to the prevalence of compression in speakers you don't neccesarily need higher efficiency to get much louder sound....efficency does NOT equate to absolute loudness it just means less power is needed at lower volumes.)

You will have to at least double your wattage to notice an increase (only 3db gain).
How about a sub? Bass is what drains the power. By incorporating a crossover and good sub you will notice a huge increase in sound.

I also have the VR4jrs and they are a fantastic speaker. I would like to offer another suggestion for consideration. Mabe what you may want is greater dynamics not just spl. I found that by upgrading my powercords and speaker cables I was really able to get my room shaking. Most of the time I use a 16 watt Art Audio Carrissa and when I really want to rock I have a 50 watt ML-11. I upgraded to Shunyata Python on my preamp and Anaconda on the amp and biwired Analysis Plus solo crystal oval speaker cables. The improvement in thunder from the speakers is huge. Your speakers can really deliver the goods when fed a really good signal.
Hope this helps. God Bless, Bob