frankly for a power consumption like this..
I'd pick tapped cells and bolt them to copper bus bars with copper bolts..
that way you can use the same busbar for initial levelling and final mounting...
and in case a cell dies for one reason or another it takes two bolts to replace it (well more or less two)
Also since tapped cells are usually of much higher capacity you can reduce the cell count
in your case to a 5P pack instead (still 80 cells which require serious precaution)
... hmm... how about premade 12V LiPo batteries (come in motorbike sizes usually)
overall not more expensive than DIY I'd say but professionally made (if not the cheapest chinese crap you could find that is)
benefit.. you can set up your system with same size LeadAcid first
and swap for LiPo packs as you go just to reduce weight a notch
60v@100A would require a 6000w controller? Are these controllers not smart enough to keep themselves from burning out?
controllers like those cannot current limit (well most can't let's say)
current is limited by the bottleneck which in this case is the motor coil..
if IT draws 60Amps the MosFets will deliver those Amps.. (up to the point where they overheat and cook off their case)
the magic smoke routine we all know and love

depends on cooling (or 'heatsinking' mostly)
the same MosFet actively cooled can reliably deliver 100 Amps that'll boil off in an instant under 20-30Amp load uncooled.
That's why a controller would have to constantly measure it's own temperature (a nasty task in itself) to prevent overheating without throtteling the power too much...
Such controller would be rather expensive.. in fact more expensive than an identically rated controller that just uses bigger MosFets.
...
Anyways:
kelly has a sinusoidial 120° brushless controller with 50Amp continuous and 120Amp peak
but it's twice as expensive as the aliexpress one:
http://kellycontroller.com/kls7212s24v-72v120asinusoidal-brushless-motor-controller-p-1348.html
frankly.. IMO still the much better option!
'sid