Ideas for used SS amp

Looking to sell one of my Cary V12R's and get a SS amp with higher power to open up the bass units on Von Scweikert VR4 HSE speakers. I am considering the Levinson No.336 and the
Pass X350. Any views or advice would help.
Moscode 401HR. Excellent match with the VR4 HSE.

IMO, the Moscode's tube rolling flexibility with the input and driver tubes
helps the VR4 HSE's top end, which can be a touch grainy with pure solid
state amplification, IMO

However, the Levinson and Pass are both good options.
Clayton amps might be worth a look as well.
I was planning on using the one V12 for the top end and a used SS for bottom,right now I'm using 2 V12's.
If it's just for bass, then why not get a used Hafler and save some big $$$.
2nd the Hafler suggestion. ie:( The DH-500 will drive you up a wall with it's fan noise. Other than that; they're a potent bass amp. The TransNova 9300/9303 and 9500/9505 are all fast and testicular(with no fan) which makes them excellent woofer amps. You'll have to attentuate whatever you get to match the drive of the amps. A Synergistic Research AC Powermaster will make a world of difference with one of these, BTW.
An Acoustat TNT200 is a wonderful bass amplifier. I had one driving a pair of RH Labs subs and it worked and sounded superb.
Maybe one the older Jeff Roland Design Group amps might work well for you;several have shown up used in the last few weeks
Krell FPB 300cx. I use it with VS VR5 HSE's and they are a perfect match. Musical and with tight deep bass in spades.

I'm not sure I would use something as good a the Pass just for bass, not if you might be going full range in the future the Pass is one of the better choices for high-powered SS -- do you need that much power to drive the VR5?
The Carver zr1600 has variable gain to allow matching the Cary and can be bridged for massive power and shorter cables.
If you are looking to sell one of your amps I am assuming you are vertical bi-amping the pair. I am surprised that you find the bass lacking, but I have never heard your speakers. I have Alon V MKII bi-amped. the speakers are not overly efficient. I changed from bi-amped Sim Audio ss to the cary v12r and have been very happey with the switch. I would advise keeping the second v12 and auditioning a ss amp before making the final decision.