10mm Ti all over is too much, you would end up with over 70kg of Ti which leaves you no weight left for motors and discs or batteries or electronics.

Make it 10kg front and back (because thats where its needed the most) 6mm on the sides and 4mm on top. That will leave you with 55kg of Ti, so a little more breathing room to fit the rest in.

2600 NiMh, I presume 2600mAh NiMh cells. For NiMh those kinds of capacaties are low, for a heavyweight I would only use 3000 mAh or more wether it is NiCad or NiMh. Also you dont stat how many packs (a pack is either 6V, 12V or 24V) you would use back to back (that is called in series, making the voltage go up (12+12+12+12=48V), then how many of these series you would put parralel (2600mAh is so low your batteries would melt or blow up if you put a LEM or Magmotor or Etek on them, let alone 2 Magmotors and an ETEK at the same time). By putting your series parralel you increase the amount of current they can deliver. So you can power stronger motors without burning them out.

In your case, 36V would be sufficent, mAh I would say 11000 at least. so 3 12V packs in series (36V), 5 of those series in parrallel(2600*5=13000mAh). That is roughly 10kg worth of batteries (150 cells in total of 70 grams per cell).