firstly, have fun with this! Secondly, I personally dislike playing anything longer than a 34" scale length instrument, so that limits me.
I've owned btb 6, carvin six, esp 6, actually several sixes. I currently own two - a peavey 6 (grind, 35", highly modified to active and with truly excellent setup - an amazing bass when modded properly), and my own custom kit bass which is 6 string 34" scale.
I play the 34 all the time. I never play anything else unless I need fretless etc.
I play the 35" and have issues with misfretting - because I play all the time and 35" scale loses your muscle memory, and I dislike the stretching so isn't worth it to me to learn... and the B string on my 34" basses are excellent, and I dislike the 35" scale for small strings like the C string (tension gets pretty darn high).
So yea, for me.... scale length matters most, so I'd be looking at SR series ibanez and similar products.
But... there are lots of amazing instruments at various sizes... so what a plethora of choices you have here!
Good luck!