I'm a bit confused here. What is an "003x"? In any case, while the 003 interfaces(console, rack and rack+) are not longer supported, the are all still working for many folks on the DUC, up to and including PT1018
I am also confused on how you are using the Scarlet interface with the 003(unless you have it connected via lightpipe, which makes perfect sense)
So, you should be able to just pick any retailer and buy either a perpetual license or a subscription(which needs to be renewed every year). You could also search for a second-hand license for PT11 or 12(my 2 cents, 12.4 is a dandy spot to sit on for a few years)
Last 2 cents, you are moving to a newer(and 64 bit) version of Pro Tools, so do it smart(and cover your *****ets). Don't do anything to your current system drive. Buy another drive, clone FROM your current drive C:, then remove your current drive and install the fresh clone. Next; uninstall/delete Pro Tools and every plugin you own(or just do a fresh OS install on a fresh drive). No doubt you're asking "why do I need to do all that?" The answer is; 2 reasons:
#1-every plugin you now are using is RTAS and PT11 (and newer) NEEDS AAX64 plugins(so all the old installation is wasting drive space)
#2-if something goes sour, you can stick your original system drive back in and get work done(and figure out solutions at your convenience, instead of ripping your hair out because you can't work at all until you figure out what's wrong)