Getting a 1.3 Kickstart is pretty easy. Because of kickram size, going beyond 1.3 isn't feasible from floppy kick (unless you're ratte.. ;-).
One kual thing I like with my A1000 is the Kickwork disk.
It's a utility Piru wrote (I think he wrote it??) that will let you create a kickstart floppy with a regular format smaller Amiga partition that you can install most of Workbench on (If you powerpack all the executables, you might be able to store it all). So 1 floppy will take your A1000 all the way to Workbench.
As for expansions, I'd head over to amibay and check on tomthul. He had (has?) an internal RAM expansion IDE board he made.
I didn't get it tho, as my A1000 already has an Insider, so I can't talk from experience, but the people who got them seemed to like them..
Also, you can go higher than 1.3, if you buy an adapter, some ROMs and are willing to do a little bit of soldering to your A1000.
Congrats.. I think between my A1000 and my A1200, I have most of what I want covered Amiga-wise..
desiv