There was another very good thread on a similar topic a while back. Unfortunately, a thorough search of the archives turned nothing up.
First of all, i would suggest the following:
1) Start with efficient speakers that are of "normal" impedances. This opens up all kinds of doors in terms of amplifiers to choose from.
2) Pick components that are on the opposite end of the spectrum from what you already have in your first system. In other words, if you have primarily all SS gear in the first system, try tubes in the second system. This will produce a LOT of fun and learning while giving you an even bigger list of experiences to draw from in the future.
3) Try to work as many "DIY" ( Do It Yourself ) type projects into the system that you can. This will once again add a lot of fun and hands on experience / learning while also keeping costs down to the bare minimum.
4) Pick up a copy of Vance Dickason's "loudspeaker design cookbook" and a subscription to Audio Xpress
5) Keep us posted as you proceed : )
Honestly though, try checking out some of the little ASL's tube monoblocks ( less than $250 a pair ), try modifying a PAS 3 preamp or build a Bottlehead unit from scratch ( less than $300 ), build a single driver full range speaker system or some simple two-ways ( less than $300 for all parts included ), build all of the associated interconnects, speaker cables, power cords, etc... ( less than $300 ), find good yet inexpensive "old but reliable" source components and then work on "tweaking" them into "modern day contendors" ( less than $250 apiece ), build your own rack ( less than $100 ), etc...
All of this can be done using the resources that we have available to us on the net. You can come up with something that is PHENOMENALLY musical and the most fun that you've ever had for well under $2K ( not including bizarre sex rituals or massive outings to restaurants of fine cuisine ). Of course, this takes into account that you are willing to get your hands dirty, make mistakes, have a selection of tools available and are up to challenging yourself in ways that you may have never done before. Either way, it would provide you with both a "hobby" and something to be extremely proud of when all is said and done. Sean
PS... This would be a GREAT way to introduce a youngster to the joys of hi-fi too !!!