Braided lines I've found make a great difference .  Perhaps good slotted rotors and good pads like ultimates or similar may get you where you want .      In saying that I've used the RRS struts with the 300mm slotted rotors and pads work brilliant for me for street and the odd track day . Something like the 300 rotors and twin piston calipers are nice 

i guess the next question is how fast it's going to be going before it needs to stop and how often?

I've never raced one, so no idea how they go or if better pads/slotted rotors are much better as with braided lines and race brake fluid.. 
@Bob Valdez is setting up a race car AU currently but was considering an XE/F but can't remember what brakes he had planned, perhaps he would have some useful info for track days and brakes. 

hey Dean,   Thanks for the great info.  It's going to be mainly a cruise car but I would like to do the odd track day at Queensland Raceway and Lakeside so I would like to upgrade at least the pad and disc setup if not go a little larger.  

only difference with the V8 was rear discs, Vented on XE XE   (even though EB V8s had solid discs)  some say the V8s had PBR front calipers (iron ones like XC) but I've seen the Girlock (basically XF ones) on V8 cars also, and believe they are basically same performance wise. XE Ghia had rear discs 250crossflow standard (same with fairlane/LTD) they were basically V8 brakes other than the potential different front calipers(older Vs Newer)   Hoppers stoppers do a "big brake" kit, which uses bigger rotors and AU series 2/3 or BA calipers from memory (could be commodore for all i know)  these may need bigger wheels than 15" 
you'd then at minimum need a proportioning valve as the fronts will over power the rears i would imagine. 
very expensive, how fast are you going to be going?    

I'm sure this has been brought up before but I can't find anything.

I'm looking at a XE 250xflow manual and Ii'm wanting to do say 4-6 track days per year.  Is there much difference moving up to the factory 351 brake setup?? I'm thinking surely the V8 stuff is more robust especially with slotted rotors and track pads.

spot welded and stitch welded, will need welding  

Does this part of the frame unbolt? I have access to an XF roller if it's easier to just pull parts off that.

they aren't stuck on as well as you'd think. they should be.    if you can beat it back into position and weld it back on securely it's probably fine.  (i bent a caster rod and lower control arm once, and it didn't pull that part off surprisingly)   i'd avoid parts sold by suzuki super on ebay..  other than just cheap parts are probably crap, i'd be more inclinde to see what's stuffed and ONLY change what's worn out .
idler arm, probably all just as crap as the next one from any brand.. tie rods usually aren't shagged, if they aren't moving keep them.. upper and lower ball joints, i've heard the WASP ones are the better cheapies. REPCO branded ones were supposedly good if you want to buy from a shop, or 555 brand or TRW being the better brands.  
 

How fucked am I?

https://www.ebay.com.au/itm/220873735667?fits=Plat_Gen%3AXF|Model%3AFalcon&_skw=xf+falcon+ball+joints&itmmeta=01JQGC9TAS5YJYK3070QEN5783&hash=item336d19bdf3:g:wS4AAMXQ1PNRaVI9&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1cffHdUR5aWsbdERj%2FJnWStUVF6ZvCL%2BjlUBaCKSXar0BVp%2FoRhUwxz74Fiqxmk%2BLiL7K0JlCm5v6QRHrWZxXAtKYlRY1R9%2Ff55yaTlkUDVEYMjBi90s80EUu5KnZ9eSlQ4cUHF%2FvXU9fWymWGjdhjXabJcCivqndJu%2FLOpT3M7KpwT7jRjd0rh6bBbaLrswQJqs4CJJbggPF4pm%2FJjZiq8rcjbu54DadPaIY1ZPfFKgifMnFJ9lIZ182ACGY0a4gj6YRFHwS69M%2BD6DS50qM9KEum4pldpHrolbdbClDVGHA%3D%3D|tkp%3ABFBMwqWnjLxl Anyone had any experience with this brand or know anywhere better/cheaper?