Splitting a 10 gal PM partial boil batch - can I do it with what I have?

Dis here is what I got:

10 gal beverage cooler mash tun
8 gal SS brew kettle w/ ball valve & thermometer
50' CU immersion chiller
(2) 6.5 gal fermenting buckets

Dis here is what I wanna do:

Use the mash tun to partial mash (2) 5-gallon batches worth of beer, and use the brew kettle to partial boil it with a late extract addition. Split the wort between the fermenting buckets and make up the volume with bottled water.

What "gotchas" do I need to be aware of?

Sounds fine to me

Are you making two different beers from one mash or one beer that you want to split to two fermenters?

One beer split into two fermenters. I think it'll be okay, even though I know I'll have two slightly different beers, not matter how careful I am to get the wort evenly split. Just wondering if anyone had experience to the contrary.

I have done this with a beer I make that takes 3 gallons of wort and 2 gallons of cider. I put 3 gallons of water in each fermenter and marked them. When it turned out that I had less than 6 gallons post boil I topped off the 2nd and dumped both back into the boil kettle to mix then I filled each fermenter to the 3 gallon line and added the cider kind of a PITA but it was definately well airated