Split charge battery advice

I've got an appache 13000Ap winch to fit to my disco 1 R reg 300tdi and am also planning to put a split charge system in.

I already have a snorkel in place which means there is (some) space in front of the air filter. Having measured the space if I move the power steering resviour a bit then I have 240mm (width) to fit a 2nd battery. The problem I've got is that the battery I use on the other side won't fit (1000cca 90ah). Having looked at various options it looks like I can't get a matching battery of a smaller size in there. Without spending stupid money the largest battery I can find is 63ah 610cca but I've read somewhere that for a winch I need something with at least 660cca?

The winch specs are:

Line Pull (lbs) - 12DC cucrrent A

0 - 100
4000 - 220
8000 - 330
13000 - 450

So I have three questions:

1. Does it matter that I 'm putting two different types of battery in the same system? (BA2685 | T-Max Split Charge System)

2. I take the spec to mean that I need 450ah when pulling 130000lbs which will almost never happen plus I already have a 1000cca 90ah in place. So I have spare capacity in the smaller battery and should be fine with most pulls considering I have two batteries?

3. When connecting the winch wiring up would you connect it to the smaller of the two batteries or go directly to the larger battery?

Also I don't want to locate the 2nd battery in the boot as I need all the space I can get in there!

Thanks for the help!

Ideally use same battery but not essential. Others may scorn this. I think different batteries can cause overcharging?
You dont need two batteries to run a winch. My advice would be to buy a massive single battery. If your worried about draining it get a decent booster pack. Much simpler.
Connect it to the biggest one as when engine not running and batteries isolated this will run the winch.

I have a t max fitted to my disco 1, I got a new battery to use for starting and used the original (old) battery for the winch, it drops in the space in front of my air box, the tray is fitted as standard, I think! just had to make a bracket to hope the battery down!

sorry "hold" the battery down!!!!!!