You WILL NOT succeed!
- Sorry for being so negative

If you read around a bit, you would find out that current Dual Layer burners - only write in Opposite Track Path (OTP) - not Paralell Track Path (PTP) which is what the PS2 needs.
Also - the PS2 uses Logical Block Addressing (LBA), so does not always use the TOC to find files - it just jumps to logical addresses on the disc - so if you burn with a DVD+R Dual Layer using OTP - you have no chance.
People are trying to unpack the assets and re-encode the layout file using Hex, but even this looks in vain.
The only slight glimmer of hope is that DVD-R Dual Layers have been quoted as supporting the possibility for PTP writing - but that remains far from fact...
Shrinking it is also impossible - due to it still seeking to the second layer...
I think the best bet, is the HD Loader guys actually getting their programs working with Dual Layer rips - that seems the easiest way forward for now...
Good luck though - don't let me deter you! 
MC