Unless you don't have another Amiga that runs 3.1, I would stick with 1.3 on the A1000 and use it mostly just for games. Look for an AdIDE w/ShuffleBoard for an internal hard drive solution, or find one of the many external side expansion hard drive enclosures.
For the ultimate A1000, find one of the 50 GBA1000 builders that have decided for one reason or another NOT to complete their project and get their motherboard and any parts they have already found for it. The GBA1000 is a great board which is almost equal to the A3000 in performance and has a couple of companion projects for flicker fixer, or even a PicassoII equivalent graphics card.
I have one of those motherboards, but plan to keep and complete it myself one day.